iFi audio GO blu

GO Blu is iFi’s entry-level DAC-AMP, primarly focused on Bluetooth connectivity, high miniaturisation and straightforward operation. It retails for just below 200€ and I got a temporary loan unit for review purposes which I analysed for quite an extended time. Here’s my report.

Features and description​

Externals​

The Go Blu is a minuscle device, approximately the size of a 9V battery but much lighter in weight (just 26g).

It carries an on-off button, an options button, and a volume knob which also has a button as its central part.

Phone outs, and a status LED are on the top side of the device. On the bottom there is the USB-C port, the microphone hole, the power LED, and a futher pin hole for hard reset.

The accessories package is quite limited: GO Blu comes with just a short USB-A/USB-C cable and a soft carry pouch. No USB-C/USB-C cable, let alone Apple cable are included, nor – oddly enough – a shirt clip is bundled inside the box.

Internals​

Unlike so many competitive alternatives on the market, GO Blu is not designed around one of those “single chip does it all” items, but is rather a fully articulated dac-amp device, with separate communication, dac and amp sections, just “miniaturised” to fit an extremely small and lightweight footprint.


https://ifi-audio.com/wp-content/uploads/2021/09/iFi_GO_blu_Lowdown_02.pdf

Connectivity is assigned to Qualcomm’s QCC5100 chip, the latest or one of the latest releases in its class by the wireless techology leader. The DAC section is centered on a 32-bit Cirrus CS43131 chip, sided by a separate hi quality precision clock. The amp section follows a full dual-mono design, and exploits some iFi proprietary technology called “Direct Drive” whereby they avoid using output coupling capacitors to get an even cleaner result on even other conditions.

Input specs are quite limited in terms of accepted formats: just PCM and only until 24bit / 96KHz. No higher res PCM. No native DSD. No MQA. The meta-message by iFi is quite evident here: focus on doing less, at higher quality.

Output specs (find them all here) are quite impressive: up to 5.6V @ 600ohm load on balanced output (half of that on single ended) and a promising 245mW @ 32ohm load on the opposite end (always on BE). Output impedance is below 1 ohm on both ports.

There’s a 6dB gain which is applied “automatically” as volume goes up – read more under Volume Control, here below.

The on-board battery while small features 450mAh capacity, and offered me – based on my typically low-ish playback volume, and always top-rank digital resolution – around 9-10 hours of operation.

Input​

GO Blu is mainly conceived as a BT DAC-AMP device, and BT performance is in facts ace both in terms of features and results. The pairing process is straightforward and I had no problem with any of my owned devices (phones, computers).

GO Blu supports BT 5.1, and a whopping array of different codecs including AAC, AptX (Adaptive, HD and Low Latency), LDAC and LHDC/HWA. The LDAC/96 implementation in particular is very solid and – when paired to another known-good-LDAC capable device – I was able to get at least 10 meters away on open path, or 7-8 meters with 2 walls in the middle, with zero dropouts.

The USB-C port on the bottom of GO Blu main body can be also used as a digital input. Again, connectivity proved straightforward both when attached to my PC (directly, and via the Nano iUSB) or to my Android devices – on which I use 3rd party sw players e.g. UAPP and Roon.

Didn’t try Apple ecosystem devices, which are declared as fully supported nonetheless.

Existing connectivity type will take priority: if GO Blu is connected somewhere via BT, a subsequently established USB connection will “not to work” – and similarly, if I have GO Blu on BT pairing mode, but not yet BT-connected to anything, plugging it into a USB data source will kill the BT pairing process, which will not resume for as long as the USB link stays on.

Finally, GO Blu has a very good working microphone on its bottom, which is straightforwardly used for calls and phone assistant interaction. The mic quality is above average at the very least, and Qualcomm’s built-in ANC works a charm: I could use it as an office tool for a while with great satisfaction.

When using GO Blu as a bi-way communication device, short-pressing once on the volume knob’s central button answers the incoming call. Long-pressing ends the call, or activates the phone assistant.

Output​

GO Blu comes with two phone output alternatives: a Balanced 4.4mm option and a 3.5mm Single Ended (S-Balanced, actually). The former is by all means the one to go for whenever possible – more on this later.

Neither is configurable as a pure Line Out.

Volume and gain control​

The volume knob is apparently well designed and feels solid and precise. iFi is particularly proud on the Swiss tech they added on that, I got no competence to confirm or dismiss but a fact is I couldnt appreciate any audible volume unbalance above 2% or something, and I did witness supersmooth and cracklefree operation for my entire (long!) assessment period.

On the GO Blu iFi chose to integrate gain control within the volume knob excursion – they call it “automatic gain”. In a nutshell, GO Blu is offering low gain until 60% volume level, then it quickly applies a +6dB gain from there on.

In general, I’m not a high gain fan to say the least: the higher the gain, the higher the compression especially on budget (read: sub-multibuck) class devices. High gain to me can and should be used with high impedance loads only, and that’s why I don’t particularly mind having a classical separate “gain switch” for that.

On the other hand I do see the point iFi designers are making on seamlessly integrating gain and volume controls, clinging at non-specialistic users who will simply not want to care on learning why and how they should or should not engage High Gain, and just want a device that “does it right, automatically”.

What makes the equation solve correctly in GO Blu case is that that little device delivers a whopping high level of current already at low volume marks. Which means that most if not all mid & low impedance devices I connected to GO Blu went nicely loud and dynamic (!) already at moderate (way sub 50%) volume levels, thus never needing to engage the High Gain mode. Plugging my HD600 required a deeper volume knob excursion, and -correctly- ended up into +6dB gain territory. Good job!

Other features​

Software and Firmware​

Like all iFi devices GO Blu allows for easy user-operated firmware flashing. In this specific case, operations can exclusively carried out from an Anroid host though, so be aware!

There’s currently only one GO Blu firmware version available, released last January 2022 – which must be flashed in should the device come with an earlier version as previous one(s) were, frankly, buggy as hell.

On the other hand, iFi offers no host software to remote-control / remote-configure GO Blu. Nothing in the line of what E1DA does for 9038x, or Fiio for BTRx, etc is available. Too bad.

Alternative reconstruction filters​

GO Blu firmware includes a sort of “easter-egg”, allowing the user to switch onto an alternative DAC reconstruction filter by following an undocumented button-pressing sequence.

To access such feature one needs to turn on and connect Go Blu (BT or wired, doesn’t matter), then triple-short-press the Power Button. At this point, single short-pressing the Options button (the one below the Volume knob) will toggle between two DAC filter alternatives:

• Minimum phase filter (upper LED turns Purple)
• Standard filter (upper LED turns Green)

The setting is saved, and will resist powering the GO Blu down.

XBASS and XSPACE​

On the GO Blu too iFi added two of their most appreciated “extras”, namely XBASS and XSPACE.

Both implemented on the time domain – i.e. on the already calculated analog output coming off the DAC – for superior quality results, XBASS is a bass/sub-bass enhancer, i.e. a filter enhancing all bass frequencies without impacting on the rest of the presentation, while XSPACE is a crossfeed filter, i.e. a system whereby, vulgarly speaking, “a bit” of the left channel sound will be hearable on your right channel too, and viceversa, which brings the headphone/earphone listening experience closer to that of full size speakers of course.

Both are great to have – especially on such a modest budget device – and being a late-50ies / 60ies acoustic jazz lover I’m especially fond of XSPACE, which “magically” compensates on many of those early stereo hard-panned masters with John Coltrane “fully stuck to the left”, for example, making them even more enjoyable.

To activate XBASS and/or XSPACE all it takes is to cycle-press the options button on the right side of the device, just below the volume knob. 1 press = XBASS, 2 presses = XSPACE, 3 presses = both, 4 presses = reset to none. The options led on top, near the 4.4 port, will light of a different color accordingly.

Sound​

GO Blu sounds seriously well.

The presentation range is very well extended both down low and up high, notes have very good body accross the board, and a particular mention is deserved by bass being very controlled. Highmids come accross a tad too evident, on the other end. Trebles are way airier than one may expect from such a small – therefore necessarily hw-limited – device. Perhaps most importantly, instrument separation and microdynamics are nothing short of outstanding.

Comparing by memory (I sold my unit quite some months ago) with an overall similar-featured device, GO Blu sounds significantly better than Fiio BTR5 for example : definitely cleaner, more extended, more macro and micro-dynamical.

Comparing instead with a different-featured but similarly priced device by the same manufacturer, GO Blu’s presentation is not the same as Hip-Dac – the latter is warmer down low, and less hot up high – although the “general sound quality” impression I can get from either is definitely on the same league.

As for probably 95% of sub-1K$ devices I auditioned to date, on Go Blu too single-ended output delivers much lesser quality than the balanced option next to it. Simply put, I would recommend Go Blu for Balanced only – and skip it if your main drivers are all single-ended and you don’t want to (or can!) plan on swapping cables.

Some caveats now.

One: In spite of a quite low output impedance (below 1 ohm), GO Blu’s Balanced output produces significant hiss on very low impedance + high sensitivity loads (Andromeda and such).

Two: GO Blu’s USB connection does and will charge the battery while playing, when connected to a host providing power on the VBUS wire. As a consequence, USB-connecting GO Blu directly to my PC produces audibly worse (closer, more compressed, less dynamical) output compared to connecting it through my Nano iUSB3, or to a battery-powered pure transport (eg a Tempotec V1).

Some educational pairings​

Final E3000​

I would call this an unreal pair in terms of amping authority, if it weren’t for the fact that E3000’s fixed cabling forces me into the Single Ended option on the GO Blu, and sadly it shows. With that being said, GO Blu’s amping module makes E3000 open up and sing quite well, so much as to make the pair an incredibly good “compromise option” e.g. when adopting GO Blu as a BT device and mid-fi digital sources e.g Spotify or similar.

Final E5000​

Not the best pair in the world at all for those but waaaay better than so many alternatives. E5000 is the empyric proof, if one is ever needed, of how vivid current GO Blu outputs already at very low volume positions, making E5000’s bass not “melting” into a too dark presentation as on most other lowcost stuff I heard it on. Very well done here.

Sennheiser HD600​

GO Blu drives HD600 with great authority powerwise, even from the single ended out which is the sole I could test as I don’t care putting a balanced cable on my HD600, Groove pair being endgame for those at my place. GO Blu’s “automatic gain” works greatly here.

Considerations & conclusions​

The main thing about GO Blu is that, quite simply, it sounds surprisingly good – especially so via its Balanced Ended output, which is the part I would recommend it for anytime really.

This little kid impressed me quite a lot for its very good DAC reconstruction quality, its more than decently clean amping stage, its capacity to drive low impedance and high impedance loads equally well, and the incredible life it delivers to most of my drivers.

Weren’t this enough add supersolid BT 5.1 (!) connectivity, XBASS and (to me, especially) XSPACE, and great performance for office calls, too.

What else can one want? The man on the road would probably, and justly, respond “nothing, just take my money now”.

I’m an old grumpy fellow so I always go around looking for flipsides, and GO Blu does have a few of course too: Single Ended output quality is rather unimpressive for one; output power although good is not enough for planars and such; Balanced output hisses off on very low impedance loads; well… that’s it really.

I took my sweet time assessing this device and I feel I need to particularly thank iFi Audio for the patience they had after supplying my loaner review unit back last december 2021 already! This article originally appeared on audioreviews.org, here, in april 2022.

The older I get, the more I seem to enjoy complaining. To be frank, I've gotten pretty good at it, and there is certainly no shortage of topics to choose from. One of those topics has been around for a while by now but I am no less frustrated by it - that would be the omission of 3.5mm headphone jacks on nearly all high-end smartphone designs.

I could tell you all about how the first mainstream high-end device without a headphone jack (the Moto Z, announced in early 2016) actually made sense - it was a one-off, ultra-slim phone which just didn't have the physical space to shoehorn a 3.5mm headphone jack inside. I could discuss Apple's culpability in this whole thing by removing the 3.5mm jack in their iPhone 7 series - which had the same exact dimensions as their 6 series and thus did have enough real estate. I could explain how I was impressed with Samsung for bucking the trend, then disappointed when they reversed course on their S20 models. I could talk about how much I appreciated LG focusing on sound quality - via wired headphones - until the bitter end when they exited the smartphone market.

I could tell you all these things, but I won't. The point is, lovers of traditional wired headphones, wanting a flagship-level phone in 2022, are pretty much out of luck (outside of a few obscure offerings from brands that aren't available in most regions).

That leaves us with a few options.

First is the blossoming wireless headphone market, which thankfully has shown significant improvement since the iPhone 7 days. It's now possible to buy some great sounding Bluetooth headphones from "real" audio-oriented brands such as Sennheiser, Audio Technica, and Sony. I predict continued growth in this segment, with more and more traditional audiophile brands jumping on board in the coming years.

That's great, but what about those who already have sizable investments in headphones and/or in-ear monitors, and just want to make use of the gear they already own while on the go? The answer for those folks involves either using a so-called "dongle" DAC/amp (another blossoming segment) or else going semi-wireless with a Bluetooth DAC/amp. The former is the best choice for optimal sound quality, yet the latter can still perform admirably while offering additional convenience and versatility.

But what if we could have both?

iFi offers just that with their "Go blu" which sells for $199. It's an extremely compact integrated DAC and headphone amplifier which can be used wired via USB C connection or else paired wirelessly using one of several Bluetooth options, including high quality LDAC and AptX HD. iFi packs in much of the same technology found in their larger gear, which means we get familiar sound adjustment options like XBass and XSpace, both of which pretty much do what their names imply. We also get a 32-bit Cirrus Logic CS43131 DAC chip, Qualcomm QCC5100 Bluetooth chip, symmetrical dual-mono signal paths leading to a 4.4mm balanced output, and quality parts used throughout the design. The Go blu is built in typical iFi fashion which means it looks and feels like a very well made product.



Gear
I already own a bunch of decent sounding Bluetooth headphones/IEMs. And I definitely enjoy them under certain circumstances. But when given the choice, I will nearly always go with a higher-end custom IEM from the likes of Noble, JH Audio, Ultimate Ears, 64 Audio, etc. It's a matter of comfort for one thing, but also of sonic performance - no Bluetooth IEM design comes anywhere close to that level of quality.

Which is why I used all of those CIEMs and more while evaluating the GO blu. I also tried an assortment of big headphones ranging from the Campfire Audio Cascade to the Sendy Peacock to Meze's Empyrean and Elite, and found the GO blu surprisingly capable of driving them all comfortably. For sources, I fed the GO blu via USB C from my Surface Pro and then used LDAC to go wireless from my Pixel 6. Music was a mixture of lossless Tidal, Apple Music, Qobuz, and my own library of FLAC files.



Listening
Initial listening was done via Roon using the Surface Pro, with the GO blu driving a set of Campfire Audio Cascade headphones via the standard 3.5mm output. This allowed me to play up to 24-bit/96kHz files and worked flawlessly with no drivers involved. I immediately perceived an improvement from iFi's presentation, which was noticeably more refined and potent than the Microsoft tablet's integrated headphone output. Cascade is not difficult to drive but with the iFi in the chain I heard more clarity, more spaciousness, and - very important with the Cascade - more control. The Surface headphone jack was generally flabby and bumbling when it came to basslines and low frequencies in general, whilst the GO blu gave me the proper sound I'm accustomed to with Campfire Audio's unique headphone design.

I broke out Crooked Still's Shaken By a Low Sound (folk or "progressive bluegrass" as I've heard it called) to see how the GO blu/Cascade combo kept up with the cello and bass, which at times can become complex and fast-paced on this album. While the result was perhaps not quite up to the standard set by iFi's more expensive desktop models, it nonetheless performed admirably, sounding rich and clean without unwanted bloat. The sense of bow-across-cello-string was convincing, as were the plucks of the bass. Switching back to the Surface headphone jack turned those instruments to mush, and also revealed some unwelcome grit in Aoife O'Donovan's beautiful voice which had not been there via the GO blu. Overall, this was a highly enjoyable result.

Next came the Sendy Audio Peacock. This planar magnetic headphone has an interesting sound signature - it reminds me somewhat of the Sony MDR-Z1R in the sense that neither has a textbook frequency response, yet each can still sound very satisfying. To my ears they both give more of a speaker-like experience than most headphones, even if that speaker is something like an Audio Note design which is intriguing if not exactly neutral. I suppose the sound is more emotionally appealing than technically correct - I understand why the Peacock is polarizing but I've grown rather fond of it over the past couple months.

The Peacock comes terminated with a 4.4mm balanced plug, which makes it perfectly suited for the GO blu's balanced output. This duo was warm and inviting when playing Ahmad Jamal's The Awakening, or Sonic Boom by Lee Morgan. Power seemed plentiful, and there was no shortage of drive even when playing quiet classical or jazz pieces. Meanwhile bombastic material ranging from Phantogram's Voices to Meshuggah's 1995 masterpiece Destroy, Erase, Improve did not lose the plot as they did when run straight from the Surface alone. This level of performance is what I typically associate with midrange DAPs from the likes of Cayin, Shanling, or iBasso, so it's impressive to hear it coming from a tiny $199 device. Also note that the delta here was even larger than it was with the Cascade - I could still enjoy that headphone well enough straight from the Surface itself, but Sendy's Peacock sounds downright bad when I remove GO blu from the chain.

Lastly, my headphone experimentation brought me to the Meze Audio Elite, which is perhaps my favorite headphone at the moment. It's a superb do-it-all performer that isn't terribly difficult to drive and is thus - in theory at least - less fussy than some competitors like HiFiMAN's Susvara or the Audeze LCD-3/4/5 models. And the GO blu seemed to adequately power it, with plenty of volume and a significantly improved sense of drive over the Surface alone. Still, the Elite sounded a bit flat and uninspired compared to what I know it to be capable of. Activating XBass helped a little, though I still wasn't completely sold on the combo. It pushed things too far into the analytical realm, and lacked the authority and depth I'm used to hearing. The Elite thus became less balanced, less well rounded than it usually is. Switching to the original Meze Empyrean, with its darker, warmer signature made for a much better pairing - very impressive for the compact size of the GO blu, and no XBass needed. One of the largest headphones I own paired with one of the smallest DAC/amp combo units I've ever tried? An unlikely pairing, but it certainly works.

I suspect the Empyrean could sound better still if driven from a 4.4mm balanced connection, taking full advantage of the GO blu's capabilities just like the Peacock had done. But all the Meze-compatible balanced cables I own are terminated in 4-pin XLR, and I don't have an adapter for 4.4mm operation. Still, it sounds remarkable even via the less powerful 3.5mm output. And while balanced mode may help a bit in driving the Elite, I doubt it would change the general character enough to cause a synergistic pairing. You win some, you lose some.



IEMs
I then turned my attention to IEMs, which for me would be the more common usage with a device like the GO blu. I started with the Surface again, and later moved to my Pixel 6 using the LDAC Bluetooth protocol. In both cases, the GO blu reminded me of its older siblings from the iFi lineup. I've heard quite a few over the years, and generally speaking they all had a similar signature - nice detail with just a hint of warmth and smoothness, excellent staging, and a firm sense of control. The latter is something we would obviously expect from their higher-end models with gobs of power on tap, but I've experienced it on their $400-600 devices as well - and now add the $199 GO blu to the list.

Quality IEMs can often rival or surpass many of the best full-sized headphones when it comes to giving absurd levels of detail retrieval. I tried a wide range of custom IEMs ranging from certified classics like the Noble K10 and JH Audio JH13 to modern flagships like the 64 Audio A18t, along with some lesser-known models from Jomo Audio, Cosmic Ears, Lear, and more. The GO blu handled itself just as it had with the larger headphones mentioned above - excellent dynamics and speed, no shortage of drive, and a well-balanced tonality with just a touch of added warmth. I was unable to find even a single pairing that I did not enthusiastically enjoy.

Moreso with IEMs than headphones, I found the XBass and XSpace functions to be welcome depending on the situation. XBass helped highly-neutral models like my Jomo 6R and Cosmic Ears BA4 to sound just a bit less analytical. It's a pretty subtle change for the most part, and feels more like a compensation for slightly-bass-deficient models than an actual bass boost per se. I'd describe it as having the largest boost (roughly 5dB give or take) in the lowest sub-bass regions, with that boost steadily declining as the frequency increases. By 100Hz or so, XBass is done, so it doesn't touch anything above that range. The result is perhaps more subtle than some people might desire but for my preferences it worked quite well.

Speaking of XSpace - it's really subtle for the most part. A bit of crossfeed and perhaps a slight boost in the upper midrange/treble region which generally helps flesh out the feel of a realistic soundstage. I found it less obvious than XBass, but after careful listening I have to admit it does help out with certain music. Many IEMs have a fairly direct, focused presentation, and XSpace gives them a bit more of an open feel overall. On the flip side, something that already has a tipped up response just might be pushed over the edge. So while I would not use it universally, it's nice to have the option available. iFi does allow both XBass and XSpace to be active at the same time, which for some reason I found less appealing - but maybe I just didn't find the right situation where I needed both at once.

My biggest concern with IEM use was background hiss, which I've heard mentioned from several different folks when discussing the GO blu. I try to avoid reading about a product when it's under review, but I've been told hiss is a fairly common complaint. Keep in mind that hiss has been a problem with portable amps since the dawn of time, so it's not like iFi is unique in this. But I was surprised to find that very few of my CIEMs showed any sort of hiss at all. I've got a wide range of sensitivities represented in my collection, and the only ones I recall having any noticeable noise both happened to be from Empire Ears. That would be their previous flagship Zeus XR and their old Spartan from back when the firm was called Earwerkz. Both of these gave just a bit of background hash which for all intents and purposes disappeared when the music actually played. Using the 3.5mm output gave less than the 4.4mm balanced jack but as far as I'm concerned it was tolerable in both cases.

I'm not saying the hiss issue is overblown. My sampling of roughly a dozen CIEMs is nowhere near large enough to make that claim, and perhaps there are a bunch of universal IEMs out there with higher sensitivities. I also admit that I'm not up to date with the universal IEM market, as my ears tend to dislike them from a comfort perspective. So there could be a large number of popular IEMs out there which in fact do experience hiss when driven by the GO blu. My point here is simply to document my experience that there are also a significant number of well known, excellent (C)IEMs which in fact do not have any issues with hiss at all. As with any amplifier or DAP, your (hiss related) results may vary.




Wired or Wireless?
Notice that in the above section, I didn't really separate the performance in terms of wired versus wireless. Why is that? Because there really isn't a big distinction between them. This of course may vary depending on the music, headphones, and wireless protocol being used. My experience with LDAC, using decent recordings and quality headphones/IEMs, is that it is nearly indistinguishable from using a wired connection. I notice a mild reduction in top-end air and delicacy, giving less realistic staging and ultimately inferior reproduction of spatial cues. But it's not the sort of thing that immediately jumps out at you. I also get the vague impression of reduced dynamics, and perhaps slightly less clarity overall. Imagine looking out through a nice clean window, whereas the wired connection opens that window for an even more transparent view (there is no window screen in this analogy, if that helps the visualization). Again, all of these differences are such that they aren't obvious during casual listening, and certainly don't ruin the experience even when listening closely to excellent recordings with reference-caliber CIEMs.

Switching to aptX HD using the developer options on my Pixel 6, I notice a bit more of a "hazy" feeling, with softer transients and another general reduction in clarity. Overall still quite enjoyable and still not trivial to distinguish compared to a lossless/wired connection. Below that, standard aptX was where things became a bit more obviously "wireless" sounding if that makes any sense. Certainly not terrible but the difference was more pronounced when listening closely. I could (and did!) still enjoy the music even with this relatively-compromised choice. Lastly, dropping to the basic SBC codec is where I drew the line and said "no thanks", due to the very obvious compression artifacts and collapse of realism - as expected using SBC. I did not try out the remaining CODEC options (AAC, aptX LL, HWA) so I can't comment on how they perform. Bottom line: for me, using the higher-tier Bluetooth connections did not hinder my musical enjoyment in any way.



Odds and Ends
One thing which did hinder my experience was the lack of any sort of clip on the device. If I'm wearing a shirt with a front pocket, it's not an issue, but much of the time I don't have any reasonable place to store the thing during active use. If I'm just sitting at my desk listening, it's fine, but for on-the-go use I find it less than ideal.

I had a whole extra paragraph here with further grumbling about the missing clip (I warned you about my love for complaints!) but I now notice that iFi offers a great little leather case, complete with clip, for $29. So that solves my issue nicely. I would like to see it offered in additional colors in the future but I'm just happy to see anything at this point.

In terms of battery life, I'd call the GO blu "satisfactory" in the best sense of the word. I was typically able to get anywhere from 9-12 hours out of the thing, depending on CODEC, volume, and headphone choice. That's impressive for such a tiny device, and easily exceeds the rated time of 8 hours, so I'm quite pleased with it.

For those of you who think you might have zero need for a wireless solution - just be aware that hard wiring isn't always possible. For example, did you know the popular Google Pixel phones have historically had issues with USB audio out? It's not something I had heard anyone mention until I picked up a Pixel 4 XL back when it launched. I plugged in a USB DAC which I knew to work with various other Android phones, and went to install the always-useful USB Audio Player Pro, only to find... it crashed when I made a connection via USB. I tried various other apps such as Neutron and HiBy Music, and while they didn't crash, none could pass a digital signal out to my DAC. Did some searching online and found other people having the same issue. At the time I assumed it was a bug.

Fast forward to mid-2022, and Google is just now fixing the issue. USB Audio Player Pro did not even show up on the play store when searching on my Pixel 6, until last month or so. Sideloading the APK resulted in immediate crashing - the same behavior I experienced a few years back with my 4 XL. In short, until Google fixed this problem (which took them several years), wireless audio was the only option for Pixel users. If it could happen to Google on their flagship lineup, it could happen with future phone releases from other brands too. So it's nice to have a device which side steps that problem whilst losing very little in terms of sound quality.



Conclusion
iFi's little GO blu is the type of device that is easy to overlook. In a sea of more affordable "dongle" format devices from the likes of Questyle, iBasso, and others, it might not grab the same amount of attention. Likewise, iFi's own lineup contains half a dozen quality DAC/amp options in the sub-$1k price range, all of which have great reputations for performance and value. Still, none of those offer the one-two punch of USB plus Bluetooth connectivity, which the GO blu handles without compromise. It really does deliver a large helping of iFi's proven performance, despite its miniscule size and relatively low price.

I will keep this short, because you are here for the testimonial and not an essay. I have been testing this along with the qudelix 5k with a Sennheisser +Drop HD8XX on a windows machine. First of all, the Bluetooth range on these is relatively weak. But the range is not a deal breaker depending on how you use it. Built quality is okay, and it certainly looks amazing. The volume knob, and its ability to sync volume with windows/android, superb. The big problem is the Sound. On SE, the HD8XX on the go blu sounds great, on the balanced on the other hand, if you are not connected to USB, there is a lot of unpleasant noise/distortion on the low end of the frequencies, it is obvious to me that they cannot handle the HD8XX above 40% at least. The go blu was my first experience with iFi, and from that I understand that they basically ask too much money for their gear, a common strategy for the clothes or any other 'objective' industry, but like cmon . No software, okaish build, great aesthetics, poor quality control, big price tag. Reminds me of chifi, or luis viton, I can do better for sure.

The iFi Audio Go Blu was sent to me by the seller in exchange for money. The seller did not ask for anything other than payment, therefore, although I will do my best to be unbiased and sincere as always, you may want to consider that this product didn't cost me any less than it will you.



Intro…

The title of this review on YouTube, in Spanish, is "ok, they were right". This title is actually a response to all of those that have been praising this little iFi device for quite some time. I suppose the title could also reflect some of the negatives of the device pointed out by others as well. This device is not perfect (what device is?), but I'll get on to the good and bad parts in a second.

First I just wanted to state the obvious. The iFi Go Blu is not a product that I know nothing about, as is the case with quite a few of the things I review. I have been paying attention to the Go Blu since it was announced and have been procrastinating the purchase ever since.

My main reason for putting off the purchase was that, as I have said plenty of times in the past, I am not a huge user of Bluetooth. I do use Bluetooth, I have nothing against it, I just always prefer wires when possible and only choose BT for convenience. So, I kept telling myself that I would just send up putting the Blu in a drawer and not use it.

I did keep following the threads and discussions though, and finally decided that I had to give it a try. This means that I already knew the positives and negatives opinions of others and had a preconceived expectation when I received the device. Whether this has any influence on my opinions that I am about to post? Maybe. As I said, I always try to remain unbiased but I am only human

Anyway, less rambling and more reviewing!



Presentation…

As with all iFi products, the packaging is fairly simple but well done. There is nothing special about the presentation or packaging but it never feels like it has been thrown together.

Inside a simple white box with an image of the GB on the front, we receive the Go Blu, a USB to USB-C cable, a drawstring bag for transport, a simple instruction card and the usual warranty card.

Nothing extraordinary or unexpected (except maybe for the bag).



Build and aesthetics…

Both the build and the aesthetics are excellent in my opinion.

The device has an elegant look to it, while breaking away from the typical blackness that is commonly found on so many other devices. The copper coloured plate that decorates the front along with the matching volume wheel really makes this look like something special. If we took away those two elements it would just be another black plastic box but 2 simple touches make all the difference.

Although the device is plastic in its majority, it seems to be well built while staying very light. The wheels and buttons have a good feel to them and work without flaw, with no noticeable looseness or rattling.

All I can say is that the Go Blu looks and feels great.



Functionality…

Let me preface this by saying that as soon as I received the Go Blu, the first thing I did was upgrade to the latest firmware, currently v3.05 I believe, which has some features that may not be available on earlier firmware releases. As far as I am aware, there is no way to update this via windows, however, I do believe that it can now be updated via iOS (but don't quote me on that as I don't have an iOS device, I just seem to remember reading that it could now be done).

The Go Blu is a unit that is very simple to operate with one hand and the various buttons are well laid out for easy access. Looking at the front we have a single button on the left (centered) and a wheel with a push button center, along with another button just below it on the right hand side. On the top we have the 3.5mm SE and 4.4mm Balanced outputs, along with an indicator LED, with a USB-C connector in the bottom of the device and a charging indicator LED.

The single button on the left is for power. Holding it down for a couple of seconds turns the unit on and off. While powered on, pressing the power button twice will trigger the voice of a lovely British lady, who informs you of current codec and sample rate. The same lady informs you of the codec in use each time you connect to your device.

Three clicks of the button enters filter choice mode, which can be cycled through standard and minimum phase by pressing the right hand button of the device. These are identified by the colour of the led on the top of the device, green for standard and pink for minimum phase. Once selected, confirm choice by pressing the power button again, three times.

The dial on the right hand side of the unit is the volume wheel, with a center button for play/pause etc.

The wheel is very sturdy and has points that it clicks to. This volume wheel actually controls the Android volume (when connected to an Android device of course) but it does it in much smaller steps. For each increase by the androids slider (in the case of a phone), you get three clicks of the wheel. That makes finer adjustments easier and much more precise.

In the case of none Android devices, I am not actually sure how the volume control works. I have used it connected to my non-android DAP via USB, with the USB output set to "fixed", and the Go Blu has controlled the volume fine without any changes reflecting on the DAP. I also found that when I used it via USB with my DAP and connected via BT to my phone, the volume level of the phone is controlled at the same time as the music playing. In other words, listening to music via USB, when I increase or lower the volume of the music, my phone also increases or decreases at the same time. So it is somehow controlling both volume levels together, even though the DAP is set to fixed. As I said, I have no idea.

The button that is in the center if the volume wheel uses a multiple click set up. One press plays or pauses the music, two clicks next track, three clicks previous track and long press for activating the assistant. I don't know about other devices but these commands dont work when connected to my DAP via USB and when connected to my phone via USB (without BT), 2 clicks lowers volume and 3 clicks increases it. I also found that Android volume can react a little strangely when connected only via USB, something that works fine on windows and my DAPs.

The final button, on the right hand side below the volume wheel, is to turn XBass and XSpace on or off (along with the filter cycle like I just mentioned). From Off, one press will activate XBass (indicator LED turns yellow), another press activates XSpace (LED goes blue), one more press activates high (along with a white LED) and pressing once again will take us back to all off (including the LED).

That's it. Rather simple but includes quite a few features and manages to do so without having to rely on 20 presses of a single button or an obligatory app (although you do need an app for the firmware upgrades).




My use case scenario…

While this is probably the least useful part of the review, as you are not me, I find that sharing my use case of the device and the pros and cons I have found may help someone who is looking at a similar scenario.

As I said earlier, I held off buying the Go Blu for so long because I didn't think I would use it for what it is good at. I don't hate Bluetooth, I use it in many circumstances, but I always find that, if I have a choice and it doesn't hinder me, I would much rather hook up a cable. There are plenty of times when BT is more than good enough, most of my manual tasks are done while using a BT neckband and Spotify. I don't need to search for perfection while I have my head in an engine or something. BT is good enough, especially now, that I am happy to use it to listen to music as BGM and am happy with the neckband set up.

As a USB DAC/Amp, I felt like there were better options out there (which there are) that are dedicated to that function, whereas the Go Blu is focused on BT with USB as a secondary thing.

Well, let me just say that the Go Blu is the first BT device that has actually attracted me to listen to music with it. For the first time, I have found myself choosing it over wired set ups even when spending extended periods at my desk.

During the past 2 weeks or so, I have found that I have been content with just using the Go Blu. It has even made me get lazy and not even bother turning on my main station when getting home, just crashing directly on the sofa with the Go Blu.

But not everything is perfect and I must mention the things that could be better when speaking about a product from a manufacturer with the pedigree of iFi (especially in the portable realm) and at a price of 200€ which is not exactly cheap for a small Bluetooth dongle when comparing to other contenders with far more options.

The first negative that I am going to mention is a clip. I don't think the lack of clip bothers me as much as many others who have expressed their opinions in forums, but I do agree that some way of connecting this to your clothing would be a big benefit. The best part of BT is the lack of cables and if I am still running a cable from my head to my pocket, it doesn't really matter what I connect it to in my pocket.

The next is the limitation of 24bit 96kHz. I really couldn't care less about MQA or DSD, so then not being supported does not bother me at all. The 24/96 also is not a deal breaker but it would be nice for it to be supported when playing via USB, again, especially when the competition can do it, and cheaper.

The BT range is also not exactly the best. It will work ok with my phone on my desk if I enter the bathroom (about 5 meters away), but any more than that results in drops. This is something that is common with many LDAC devices, I have gotten used to it after using Shanling DAPs, but could be much better.

I will say that the quality of the microphone was a very pleasant surprise. I expected much worse quality and to have to hold the device to my mouth but, at least in my quiet office, I can make calls with the device on the desk with no complaints from anyone.

I am also very happy with the fact that I can use it via USB while still being connected to the telephone via BT. It would be nice to be able to pair it with multiple devices via BT but USB+BT works well for me personally. One thing to note though is that each time you unlock the screen of your phone, or use it in any other way, the music will pause.

That has actually been my main use for the Go Blu. I have had it connected either to my DAP or PC via USB, with my phone connected via BT. This allowed me to use the Go Blu for calls on both PC and the phone without any changing over. However, for some reason, I did find that certain apps (for example Zoom and Skype) needed me to manually set the Go Blu as the device in their app settings, the “use predetermined device” didn’t work.

Finally, before I move on to sound, I want to mention one thing that is probably the negative that most affects me. The background noise with sensitive IEMs. Ok, this is not present on the SE output, nor on less sensitive IEMs and headphones, but with the balanced output and sensitive headphones/IEMs, it is certainly noticeable to say the least.

This is not such a big issue for me as it would be on another device as I prefer the SE output (more about that under “sound” in just a moment) and when I am using something that really needs the balanced output, well they usually aren’t that sensitive for it to be an issue. I know that iFi sells the perfect solution to this, the IEM Match, but when purchasing one of the most expensive BT dongles (again, from a company with the pedigree of iFi), a gain setting would have been a very nice touch.

So, these are just my random musings after using the Go Blu (almost exclusively) for the past two weeks or so. Now, let’s get on with the sound.



Sound…

Where to start?

I have reviewed other iFi devices in the past and I have found that they have a bit of a colour to their sound that is representative of iFi. I might be crazy and I might be imagining it, but that is what my brain has told me I hear. A lot of that is supposedly due to the use of Burr Brown DAC chips, other things may be they way that iFi amplify the signal or even the parts involved, but ignoring the fact that maybe I am just making things up, I do feel that iFi really does have a “house sound” that is slightly warmer than other options.

In the case of the Go Blu, there is no Burr Brown chip and there is nowhere near as much room as in any of the other iFi products to use the same parts, so there is no reason for it to have that iFi warmth to it. But it does. At least to some extent and on the single ended output.

Ok, so I may have gone totally crazy and I may be hearing this just because I have read about som many other people hearing it, but I really do find (or at least my brain says it does) that the SE output is warmer and less harsh than the balanced output.

There is probably no reason for me to hear one be warmer than the other, although I haven't seen measurements, but my brain tells me it is. Using the same IEMs, with the same cable (terminated in 2.5 balanced), just swapping the adapter and from SE to Balanced, I feel that the IEMs sound harsher from the Balanced output.

Obviously the balanced output is louder until we reduce the volume level and performing a perfectly volume matched test is rather difficult with just one device (without quite a gap between listening to one port and the other), so it may be just my perception due to the volume differences, but I also feel the balanced output to be far more fatiguing over longer listening sessions.

Again, different music choices, different moods, different times of day, everything can be an influence, but as an example, I found that using the Yuan Li from from the balanced output made me feel like taking a break every hour or so, whereas from the the SE I could listen all morning (4 hours).

The XBass is great (isn’t iFi XBass always great?) although I don’t really use it that much. I have used it on a few occasions but not really too much, more for specific albums than anything else.

The XSpace is ok but unfortunately (for me at least) it is not the same as the XSpace on the iFi HFM Signature CAN. On the HFM Sig I found that the XSpace worked really well to give IEMs a bit more room to breathe up top, with the Go Blu I don’t get that same sensation of openness. It is more like a subtle treble boost (which I guess the CAN was also) that doesn’t quite give the same result.

Here is a graph of the changes in frequency response between the 4 modes (off, XBass, XSpace, XBass + XSpace):



I guess that the last thing to mention is how the Go Blu performs and sounds with more demanding headphones. To be honest, as most of my listening is done at low levels and a lot of it is quite simple acoustic based music, I probably don’t suffer as much as someone who listens loudly to Metal. I don’t personally need the speed or the volume levels that others may need.

Saying that, here are a few brief opinions on things I have tried with the Go Blu.

IEMs (in General): I have found that the Go Blu can drive any of my IEMs from the SE output without any issues. I have tried multiple IEMs and I did find that balanced opened up some of the darker sounding IEMs a little, my favourite IEMs have been things like the Jasper and the Yuan Li, running from the SE output.

Beyerdynamic Custom Studio (80 Ohms / 96dB/mW): These were actually the first over ear headphones I tried with the Go Blu, as they live in a drawer of my desk in the office. Running them from the SE output I didn’t find that I had any issues with volume or performance in general. I was actually surprised to find that I really like the combo and they make a great BT headset.

Hifiman Arya w/ Stealth Magnets (32 Ohms / 94dB/mW): I enjoyed these headphones powered by the Go Blu, from both the SE and Balanced outputs. With the majority of music I listen to, there were no issues but when listening to some heavy paced electronic music, I did feel that they weren’t performing to their capabilities. They lacked some technical performance more than actual sound issues.

Hifiman Ananda (25 Ohms / 103dB/mW): I enjoyed this combination very much. I did not find that the Ananda seemed to be lacking in any way and seemed to be as detailed as always. I actually preferred these from the SE output.

Hifiman HE400se (25 Ohms / 91dB/mW): These sounded ok with the Go Blu but somehow seemed to be lacking a bit of life. Where the Arya was lacking in technicalities, the HE400se just seemed to be a little dull in general.

Sennheiser HD6XX (300 Ohms / 103dB/mW): These headphones actually sound fairly decent on the Go Blu, at least at low listening levels. I didn’t really push these while trying them out as I had people at the side of me but I enjoyed the while I spent with them (it’s always random whether I enjoy these headphones or not anyway).

Beyerdynamic DT1990 Pro: Guess what? They sounded like DT1990 Pro’s, as they always do

That is about all I have tried out with the Go Blu, except for the Titan S that I tried out briefly today, but I will certainly be trying out new stuff I receive with it and I’m sure it will be mentioned in more reviews over time.



Conclusion…

iFi Audio seems to have a vibe with their products that invite you to listen to music. I know I haven’t had the pleasure of trying all their stuff but the ones I have, all give off this same vibe, except maybe for the Diablo. The Diablo still has that iFi flavour but is more of a “look what I can do!” kind of source than others that are more “just sit back and enjoy!”. I had that sensation with the NEO and with the HFM stack, and now I get it with the Go Blu, even though it is not using the same hardware at all.

I avoided the Go Blu for so long because I thought I would not use the BT functionality except on occasions and that there were better wired options, so it would just sit in a drawer. I have been proven wrong. Not in the fact that there are better products out there, everyone will have their own needs and things will suit them better or worse, but in the fact that I wouldn’t use it.

As I said earlier in the review, it is the first BT device that actually inspires me to pick it up even when I have wired alternatives on hand. In comparison to other things that I have been using recently, such as the Hidizs S9 Pro and the Aune BU2, it is different to both of them.

The harshness I find in the higher ranges of the S9 Pro is present in a similar way but to a more reduced extent on the balanced output of the Blu. As with the S9 Pro, I find the balanced output of the Blu to be more tiring over time. However, everything else about the Blu (except for the 24/96 limit) is superior by a mile. The build, the looks, the functionality and the fact that it inspires me to relax and enjoy the music where the S9 Pro is more of an attention seeker.

In comparison to the BU2, they are again different. I feel that the BU2 focuses on USB with BT as an extra, whereas the Go Blu is the other way around. If using Bluetooth I would no doubt go for the Blu, but when competing on wired terms, the Aune is more detailed in my opinion. Maybe more detailed is the wrong term, it is clearer with its details, whereas the Go Blu is more relaxed. The balanced output of the BU2 also avoids that harshness I mentioned, sounding exactly like the unbalanced output (in my opinion), just with more power.

I have to say that the iFi Go Blu really is a great little product. It is a perfect companion to always have on hand as it fits in an IEM case along with a set of IEMs, a couple of adapters and a USB-C to USB-C cable.

There are a couple of things that could be improved on and I would love to see more case options for it (even if they are just simple transparent cases with a clip like on the S9 Pro) but other than that, I really can’t complain.

And the final thing that matches the rest of the iFi products is that my review of them turns into a long wall of text!

*This review is also available in Spanish on my blog here and on YouTube here.

My personal set of on the go DAC/amps rotate between the iFi hip dac, Lotoo PAW S1 and on occasion, the newer AUNE BU2. The Aune BU2 gets probably the most use since it’s bluetooth and for the most part I almost always use bluetooth when I’m constantly on the move. I’ll always hardwire my portable DAC/amp when I settle in at say a family member's house or after I get to a hotel after a flight. The new iFi GO blu caught my attention for being a small portable DAC/amp that seemed perfect for my use and would still allow me to either plug in via USB or at least hold me over till I got one of my travel DAC/amps out to plug into my laptop or iPad. The GO blu is using a Cirrus Logic CS43131 DAC and Qualcomm’s QCC5100 Bluetooth chipset.


Thanks to Seb and iFi for hooking me up with a review unit. While I always appreciate stuff being sent in to test and review, It never affects the rating of my review.


Info and purchase links on the iFi GO blu can be found below

https://ifi-audio.com/products/go-blu/​

Gear used​

Topping EX5, Lotto PAW S1, iFi hip dac, AUNE BU2, Symphonium Helios, Moondrop S8, UE TripleFi 10, Meze Elite, Audeze LCD-5

Looks and Feel​

The GO blu is super small. I knew it would be smaller but I was extremely surprised when I held it in my hand. My Volvo key fob is bigger than the Go blu side by side haha. The unit has a nice soft touch matte finish and it has a little metal(not sure if real) accent which looks good. The real winner in terms of looks comes from the volume wheel. It’s a clicky wheel and it feels great rotating. This is the first iFi product that didn’t terrify me since the volume wheel has just the right amount of resistance. I experienced zero issues with random volume adjustment when it was in a pocket and on the move.

Accessories and unboxing​

We get a standard iFi box, basic user guide, tidal setup guide,the unit, USB-C to USB-A cable and finally a little carrying bag. The basics are included and that’s totally fine since this is meant to be used wirelessly.

Sound(overall)​

These final impressions were done off the GO blu connected to my Apple devices via Bluetooth. This will be what the GO blu sounded like with all the headphones I used. Things like headphone pairings or going wired will produce different results and impressions vs what my ears hear on my specific gear.


The little GO blu is a powerhouse. The bass sounds super dynamic, the mids have a nice crisp sound to them and the treble has fairly good detail retrieval. The bass hits a little harder but doesn’t quite give me the standard iFi warmth I’m used to from their other products. This is probably due to the use of a different DAC over the normal Burr Brown stuff they use. The mids have a nice accurate sound all the way through those frequencies. Vocals always sound clear and details in the voices are a little above average. The treble is where I was most surprised. I figured the GO blu might have either a warm treble or a hard time with detail retrieval for how tiny and for its price. It was quite the opposite in fact. When compared to some of the other portables I use, the GO blu was close to the top when it came to pulling in details for the detail heavy IEMs and headphones I tested with. Treble has a nice airyness that I don’t get with some of the other portables either. Is it as good as something like a $400-$600 DAC amp? I don’t think so but I can’t carry those with me like I can the GO blu. I’m super happy with the GO blu’s performance and I haven’t even started talking about their hardware EQ stuff yet.

XBass/XSpace​

Speaking of Hardware EQ! The GO blu gets both of iFi’s bass boost and their soundstage booster. The XBass is a nice and tasteful bass boost that adds a nice amount of sub bass boost to give some headphones that lack in the impact departments a little extra energy down low. I’ve heard many bass boosts and iFi still manages to be one of the best out there. The XSpace is always different with each of their devices. I’ve yet to hear two devices that have the same sounding XSpace. The GO blu’s use of XSpace is less of a soundstage enhancer and more of a treble boost from my testing. Which for the most part works out well. I don’t really have a collection of dark sounding headphones so I didn’t get much use out of XSpace but I will say it adds a decent treble boost that might give some top end energy to headphones and IEMs that may need it.

Imaging/Soundstage​

The soundstage and imaging tend to be headphone specific but DAC/amps can add a little extra on occasion. The Go blu has about average staging width and depth wise. More of an accurate presentation and lets the headphones and IEMs do their thing. The imaging was totally fine too which I expect from source gear.

Bluetooth/Wired connectivity​

So most of my testing was done via AAC Bluetooth from my iPhone or iPad. I won’t get into the whole bluetooth vs wired debate but I was super happy with the bluetooth performance and range for the AAC codec was awesome. I never had issues when walking away from my room and it lost connection about the same distance as my Sony TWS. I ran the GO blu wired into my Windows 10 desktop that has my main audio gear and through my Windows 11 Asus gaming laptop. I had zero issues from the Windows 10 desktop but I had a strange issue with Windows 11 that had an issue with volume that resulted in the GO blu having so much volume that half my IEMs couldn’t be used on the lowest volume. I blame Windows 11 for this issue but I did do a firmware update to the GO blu that had come out a month prior and that solved the issue. Now onto said wired connection. I do believe the GO blu sounded even better via being wired but it was just minor improvements and a little more noticeable stage increase. I had no issues with Bluetooth and plan to run the GO blu wireless unless I don’t have any other more powerful DAC/amps to use when I settle in somewhere.

Personal grips with the GO blu?​

I honestly have no real issues with the GO blu. I do have three small nitpick issues but these won’t be a big deal at all for most people. First would be the hiss out of the 4.4mm Pentaconn connector. This has always been an issue for iFi on their devices. I’ll give the GO blu a pass since the trade off is that it has a higher volume output which means I managed to power bigger headphones like the Meze Elite and Audeze LCD-5 to high volumes just fine via balanced. I would have liked to see them include a low/high gain to allow sensitive IEMs to have less hiss. The hiss isn’t terrible and it doesn’t bother me once music plays. The second thing would be that they don’t include any type of case with a clip on it. This is the perfect device that could make use of that type of case and I feel like it was a missed opportunity. I put the GO blu in the change pocket thing on my jeans and that’s probably how I would use it even if it did come with a clip case though. Last little thing would be firmware updating. It’s a weird app that has to be done via Android. Luckily my finance had an old android device I could use but I would like to see a way to update via Windows at the very least down the road.

Single ended and balanced power output​

iFi did normal power ratings into 32 ohm which is what I like to go by. The GO blu with output 245mW into 32 ohm via balanced and it will also do 165mW into 32 ohm via single ended. Before the Lotoo PAW S1, these numbers would have been too small for me personally(on paper) but the single ended power output is great for all IEMs and the balanced power output was perfectly fine for getting enough volume to full sized cans.

IEM pairing opinions​

Moondrop Aria​

The Aria still remains my favorite sub $100 IEMs and it pairs really well with the GO blu. The Aria maintains its fantastic “all rounder” qualities but it seems to benefit from both the xBASS and xSPACE features. The xBASS boost takes the Aria from “pretty good bass” to a much deeper bass texture with more impact. The way iFi does the hardware bass boost means there was no bleed into the mids which was fantastic. xSPACE added just a bit more top end energy which added that nice “perceived detail”. Using both features at the same time gives the Aria a bit more energy and was probably one of the better IEMs I used with the GO blu.

Moondrop Variations​

Coming in a little over double the price of the GO blu is the Moondrop Variations. This is one of my favorite IEMs and the Go blu does well to keep everything sounding smooth and wonderful. I couldn’t tell a real difference from desktop to this when using the Variations. Bass stays strong, the mids are still smooth and the treble was well maintained and pulled in some decent detail when paired with the GO blu.

Kinera Nanna Pro​

The Nanna is probably one of the best “Vocal” oriented IEMs I’ve had a chance to hear recently. When paired with the GO blu, it keeps a wonderful focus on the vocals but the bass can feel a little weak at times. I’ve noticed this IEM is fairly power hungry and the GO blu does good at keeping it sounding great. I fixed what I felt was a lack of bass with the xBASS turned on. It was just the right amount of added subbass to give the Nanna back the oomph I get from the desktop amp I use with it. I would say using this combo is perfectly fine.

Over ear pairings​

Meze Elite/Audeze LCD-5​

Unfortunately I don’t have any full size headphones on hand and I was gonna skip including full size headphones since I wouldn’t use open backs with the GO blu out and about but I was still curious what the little Go blu could do to some really nice TOTL headphones. The Elite sounds pretty good off everything I test for the most part. It does well with the GO blu and manages to stay strong and bassy but loses a little when it comes to upper mids and into the rest of the treble. Things can sound just a little hollow at times and I believe this to be a issue of power which I wont hold against a $200 portable DAC/amp. I was impressed with the performance regardless. The LCD-5 was mostly the same story. Though I find the LCD-5 a little too warm for my taste, the use of both the xBASS and xSPACE really helped bring some fun energy to the LCD-5. While you could totally use a GO blu to power some TOTL headphones, I wouldn't personally use the unit for that purpose.

DAC/Amp comparison​

Aune BU2​

The BU2 is better at detail retrieval and I personally like ESS DACs for that extra sharpness which is very much noticeable on the BU2. The BU2 also has a nice dynamic bass and crystal clear mids. The big differences here will be the size and unit outputs. The GO blu has a more powerful 3.5mm output and the BU2 has just a little extra power out of the 2.5mm jack. That will be the main reason I recommend the GO blu over the BU2. While I like the overall detail retrieval from the BU2, I think 2.5mm is mostly dead and I prefer my units to use 4.4mm Pentaconn these days. Plus size is a big thing IMO. The GO blu is easy to take around. The BU2 is about the size of some smaller smartphones so it takes up more space.

iFi hip dac​

The GO blu is simply better than the hip dac is almost every way to me. The hip dac has more power output from both the single ended and balanced jacks but the GO blu has alot more features. The GO blu uses USB-C for charging and data connection instead of the male USB-A output that the hip dac uses. The GO blu has Bluetooth which makes it a much better portable unit. Finally we have the “iFi” features. The hip dac uses only xBASS and the GO blu has both xBASS and xSPACE. The hip dac does sound a little brighter to my ears from testing but they both do detail retrieval from the headphones I tested about the same. For the purpose of being a portable transport, I think the GO blu is a better unit overall.

Overall thoughts​

The iFi GO blu has been a real treat and I plan to personally pick one up after doing the review for it. I was extremely impressed with what the little DAC/amp was able to do and it sounds great wireless as well. I highly recommend the iFi GO blu for anyone looking for a little portable DAC/amp to use either on the go or away from the desktop. I’m happy to see iFi come out with a brand new original product and look forward to checking out their Gryphon soon! Thanks for reading!

Full disclosure: @iFi audio sent me a sample GO blu in exchange for my honest review, and the opinions expressed herein are entirely my own. My review unit was supplied by AudioExchange, South Africa's official iFi reseller.

Introduction

iFi is no stranger to the head-fi community, having established itself over the past few years with a range of well-received source gear for almost any use case and budget. The UK-based company is actually a subsidiary of Abbingdon Music Research (AMR), one of the UK’s largest manufacturers of high-end audio systems, so when it comes to pedigree, iFi is not just another niche player or nameless mass-producer vying for a share of the limelight.

GO blu is iFi’s first attempt at an ultra-portable ‘dongle’, but unlike the majority of cable-tethered dongles from other brand-name vendors, Go blu is first and foremost a ‘hi-res’ Bluetooth dongle. That means it supports the highest Bluetooth codecs currently available, including Sony’s LDAC, which theoretically has enough bandwidth to stream hi-res music files (up to 24/96), albeit using lossy algorithms.

I’ve spent the past two weeks getting to know GO Blu more intimately, using it as my main DAC/amp (with my smartphone as the source), and comparing the experience to the higher-end DAPs I’m more familiar with. To say it’s been an eye-opening fortnight is an understatement; GO Blu has so far been one of the more pleasant surprises I’ve enjoyed in the hobby. Read on to find out why.


Tiny but mighty

The first thing that struck me about GO blu was not the stylish metal faceplate, Swiss-like chronograph, or practical non-slip rubber surround, but rather how small it was. By small I mean absolutely tiny – 54mm x 34mm and only 13mm thick. It’s also light, so light that iFi claim an AA battery is heavier, which is true by the way.

As tiny and light as it is, it still manages to house two headphone output ports, including a genuine Pentaconn-certified 4.4mm fully balanced socket. The chronograph – or ChronoDial, as iFi calls it – is the other striking feature. As far as I can tell, GO blu is the only dongle that features a rotary volume dial, though the ChronoDial is more than that, doubling as a click-button for pause/play, next/previous, and call answer/reject controls too.

There are two other buttons, one below the ChronoDial that’s used to switch between GO Blu’s nifty XBass and XSpace features (more on these later) and Bluetooth pairing mode, and one on the opposite side for power on/off and Bluetooth pairing confirmation. At the bottom of the case is a single USB-C port that doubles as a charging and digital data port (for wired DAC functionality), a small LED light for power state, and two pinholes, one for factory reset, the other for the built-in microphone (yes, you can make and take calls while connected with GO blu, although I didn’t try out this functionality myself).

The packaging is neat and simple, typically iFi-like with lots of information all over the box. A slide-out tray holds GO blu in its own cavity, with a small separate box for the included USB-C to A cable and velour-style carry pouch. I would have preferred to see a USB-C to C cable included considering GO blu is most often going to connect directly to a smartphone, and most modern laptops feature USB-C connectors too.

For the asking price of $199 a USB-C to lightning cable wouldn’t have gone amiss either, if only so that iPhone users would have one less thing to complain about because let’s face it, who wants to fall back on AAC?

But I digress; GO blu ships with everything you need to get up and running in the box. Build quality is excellent, and not just for the price, and the styling is unique and, if I may say so, quite stylish, more so than iFi’s usual utilitarian designs.


Swiss Army dongle

At the heart of GO blu’s functionality is a compact Cirrus Logic CS43131 DAC, which according to iFi is going to form the basis of their ultra-mobile product lineup. I can only assume there’s a good reason that iFi decided against using the traditional hybrid Burr Brown DAC that powers just about all their current devices, and if I had to speculate it’s probably because they were aiming for a much lower power draw than was possible to achieve with the standard DAC.

As it is, GO Blu’s 450mAh lithium battery supplies up to 8 hours’ runtime, depending on the headphones used and processing requirements, which is plenty for all-day use, considering it only takes an hour or so to charge it back up to full. Since GO blu also uses its battery in tethered mode, you can maximise sound quality from your phone by wiring it up without draining the phone’s battery, something many other dongles don’t offer.

GO blu incorporates the same dual-mono fully balanced architecture common to many of iFi’s recent portable products. This not only helps clean up the signal, but also provides much more power to drive even demanding headphones – up to 245mW into 32 ohms to be exact. You’ll struggle to find this much muscle in any other dongle in this price range, and even more expensive (and less portable) amps generally don’t go this high either.


Ironically the additional power seems to have caused some teething issues for early adopters, with reports of some GO blu units emitting unacceptable levels of amplification noise, especially with sensitive IEMs. In my own testing, I’ve found no such issues with my particular unit and my IEMs, so it’s likely more a factor of quality control than it is a design flaw, or at least I hope that’s the case.

Other amplification features making their way into GO blu’s spec list include DirectDrive, which eliminates the coupling capacitor typical in many circuit designs to provide a more direct signal path that, supposedly, helps further eliminate noise and reduce distortion. The capacitors that are included are sourced from TDK and MuRata, much like those used in ifi’s more expensive desktop-grade devices.

Also adapted from other iFi designs is analogue DSP functionality, which in GO blu take the form of XBass and XSpace effects. XBass, as the name suggests, helps fill out the lower octaves with a subtle dose of extra weight, an effect I can heartily recommend even if you’re using bass-savvy IEMs or headphones. XSpace is less convincing, adding a touch of air and pseudo ‘space’ to the sound, which could be useful if you’re using intimate-sounding headphones. You can also use both effects together, but I tend to just leave XBass on and forget about it.

The last arrow in GO blu’s sizeable quiver is a Qualcomm QCC 5100 Bluetooth controller. This brings GO blu up-to-date with the latest Bluetooth 5.1 receiver spec and supports almost every conceivable Bluetooth codec, including AAC, SBC, aptX, aptX HD, aptX Adaptive, aptX LL, LDAC, and LHDC/HWA. Conspicuous in its absence is Qualcomm’s newly- announced AptX Lossless codec, although I don’t believe there are any devices that support this codec at the time of writing.


Sound impressions

With so many features and so much power in such a miniature space, iFi has taken a leap of faith that all these moving parts, figuratively speaking, will click together to deliver a quality audio experience on the go. The combination of hi-res Bluetooth and 4.4mm output makes GO blu particularly potent for users of higher-end and higher-power IEMs and headphones.

I decided to test GO blu by using it exactly how I expect most people to use it: first, with Bluetooth and a smartphone, and second, wired to a laptop. All tests were done with a pair of Sennheiser IE 900 IEMs using the 4.4mm balanced output.

My playlist included tracks by Lana Del Rey, Beyries, Angel Olsen, Ane Brun, Max Richter, Def Leppard, Brandi Carlile, Britney Spears, Linda Ronstadt, Eagles, Lola Marsh, Cranberries, Carpenters, and a host of other obscure indie singer-songwriters I won’t list here. I mention these only because my taste in music will likely differ from yours, and it’s important to remember that my impressions will be biased to my preferences accordingly.


As a Bluetooth receiver

To be honest, I was skeptical about using Bluetooth for serious listening. While I’ve experienced exceptional power and quality from tiny dongles before (EarMen’s Sparrow comes to mind), this is the first time I’ve gotten to hear just how far we’ve come with wireless in the mix.

The Sony WF-1000XM4 true wireless IEMs are my go-to for ‘casual listening’, with a smooth, punchy and inoffensive sound I can listen to with ease all day long. But when I want a more involved listen with better quality throughout the playlist, I generally turn to more capable (and correspondingly more expensive) IEMs like the IE 900.

Unlike TWS, GO blu relies on Bluetooth for input only, since all the digital conversion and amplification happens internally. That makes a Bluetooth dongle very different to TWS IEMs, which rely entirely on the tiny DACs and amps built into each earpiece for sound processing. It’s a distinction I feel is important to make, in case you’re thinking there’s little difference between the two, even though they both use Bluetooth in the chain.

Pairing GO blu to an LG V30+ phone was a quick and simple process. Switching the blu on for the first time automatically puts it into pairing mode (denoted by alternating blue/red LEDs on the top panel). Once paired, it’s important to select ‘Best Quality’ under the pairing’s Bluetooth settings – if your phone doesn’t select that option by default – else you may get paired using AAC or worse, SBC.

Note that if you’re an iPhone user, AAC and SBC are your only options, so this only applies to Android users. Most modern Android phones should support the LDAC and/or LDHC codecs, so make sure that’s how you’re connected before proceeding. If you’re unsure which codec you’re paired with, double-click the button on the left panel, and a sexy voice will reveal the codec and bitrate (‘LDAC 96 kilohertz’ is what you want to hear).


My very first thought at hearing the opening verses of Lana Del Rey’s Video Games though GO blu, streaming over LDAC from my trusty LG, was a distinct sense of familiarity. This was not the sweet but smoothed-out sound of the Sony TWS IEMs; this was very much the same tone, same texture, same quality I was used to hearing from the IE 900 plugged directly to my phone, to the Sparrow, or to just about any other excellent, amplified source.

Instrument timbre is as good as I know the IE 900’s timbre to be, and layers beautifully with Brandi Carlile’s smoky vocals in The Story. Overall tonality is neutral with a hint of warmth, very much as I expected from an iFi device. This has been the ‘house sound’ since my first encounter with the venerable Micro iDSD more than four years ago, although I find the GO blu to be slightly more transparent and airier by comparison, if memory serves.

Male vocals are delivered just as deftly as female, Don Henley’s iconic performance of Hotel Californiaperformed live on the Eagles’ Hell Freezes Over a case in point. GO blu takes firm control of the IE 900’s powerful dynamic driver, pushing punchy, bouncy bass notes that hit with authority, and more complex passages like crowd noises and guitar duets are never muddied or overwhelmed, even though I can pick out a hint of smoothness that probably shouldn’t be there in some raspier vocals.

While not the most technical high-end IEM I own, the IE 900 is still very technically adept, with a generous stage, excellent layering and separation, and fairly precise imaging. To my ears none of these are hamstrung to any significant degree by GO blu as a Bluetooth dongle. It may not drive the IE 900 as precisely and expansively as the HiBy R8, for example, but the difference is far smaller than the $1800 difference in price between the two would suggest.


As a wired dongle

I have to take issue with iFi for ‘crippling’ the Cirrus DAC by limiting its maximum supported resolution to 24/96, not enabling native DSD support, and not even contemplating MQA support. I suspect these were conscious choices made by the company to either maximise battery life or reduce size and cost, but at the very least the very capable DAC should have been allowed to do its thing with PCM?

Regardless of the reasons, when I connected GO blu to my MacBook Pro, these limitations were clearly displayed in Audirvana’s control panel. However, it didn’t stop GO blu from continuing to show off with its crisp, clean delivery. Linda Ronstadt’s evocative vocals in Dreams to Dream made me tear up like a baby – as they always do when the delivery is spot on – and with GO blu, it was absolutely on the mark.

Switching to something more modern and poppy, Britney Spears’ If You Seek Amy was a bassload of fun, complete with sketchy sample quality and imperfectly recorded vocals. If nothing else this speaks to GO blu’s transparency as a source, because it’s exactly how I know this track to sound with the IE 900. The slight injection of warmth is welcome, and I could swear this is some of the best bass weight I’ve heard from the IE 900.

Replaying some of the tracks I heard wirelessly, I could try to make a distinction between the two, but I’d probably be off-target half the time. What struck me more than anything was how much fun it was to work and play with the MacBook Pro delivering insanely good sound quality with nothing more than a little dongle dangling from the USB port. I could AB and pick out minor differences here or there, but really, why?

It’s not all roses though. For example, I struggled with figuring out how which device – GO blu or MacBook – ultimately controlled volume. Turning the volume of the ChronoDial changes the volume on the Mac, but sliding the volume up or down in Audirvana leaves the ChronoDial setting as-is. Also, I can only raise the volume about 10-15 percent on Audirvana before the IE 900 becomes too loud. There’s probably a setting in Audirvana or the Mac itself that I haven’t studied properly, but out of the box, it’s unnecessarily complicated compared to Bluetooth mode.

Also, it seems I can’t pause/play or skip tracks using the ChronoDial when in wired mode. I’m not sure that’s even an option, but if it’s not, that’s one less useful feature you lose when you wire up.


Closing thoughts

GO blu appeared out of the blue, so to speak, not really aligning with anything iFi has done in the past, and yet when you use it, it makes perfect sense. It’s the ultimate expression of iFi’s portable DAC/amp philosophy – an ultraportable device that gives up very few features iFi users almost expect by now, like analogue DSP, sophisticated amplification, and a well-tuned, well-specced DAC untethered from the desktop and able to drive almost any mainstream headphone.

The killer feature, for me, is Bluetooth. It’s such an obvious feature I’m actually surprised so few of the many dongles flooding the market right now actually offer it. Considering how good GO blu sounds in Bluetooth mode – so good, in fact, that wiring it up makes a small but arguably insignificant difference to sound quality – and it almost doesn’t make sense that dongles don’t offer wired mode as an option instead of default.

That said, GO blu isn’t perfect either. While my own unit, with my IEMs, has no audible hiss or hum during playback or between tracks, but there are enough reports out there that suggest it’s not ideal for all IEMs, and that QC could be an issue. It also lacks many features that iFi have either purposefully withheld to optimise battery life and performance, or perhaps ‘cleverly’ withheld so as not to cannibalise other products. After all, if they gave us IEMatch and their famous Burr Brown DSD-capable DAC, there wouldn’t be much sense in spending twice as much on a device twice the size and harder to carry around, right?

But cynicism aside, I’m excited by GO blu, even if it is version one-point-oh. It’s already ‘better’ than any other dongle I’ve used by virtue of its ultimate Bluetooth portability and infectiously-good sound quality. It’s well made and seems to be fairly stable, and with any luck, iFi will see fit to add to the current features with future firmware updates. Best of all, it takes the IEMs I know and love, and drives them with a steady hand, infusing its own very subtle character but really just allowing them to do what they do best.

I can think of no better endorsement than the fact that, for two weeks, I’ve been using a $200 dongle instead of a $2000 DAP and haven’t for a minute felt poorer for it. GO blu is an easy recommendation from me.

Disclaimer: iFi graciously lent me the Go Blue.

Gear used:
Ath AD1000X, Ath R70x, Sennheiser HD600, Final B3

Specifications:


Source: https://ifi-audio.com/products/go-blu/

Intro and accessories:

Disclaimer - I was sent this by Ifi-Audio for my honest opinion, it is not a free sample. I will either send back or purchase after review period.




BACKGROUND

The Go Blu is Ifi Audio's latest product, this company feel like they are on a bit of a roll over the last 18 months or so with a steady stream of releases across the market. I already own the Zen Can/DAC Sennheiser Signature pack and I really like the sound quality and function from the duo. I also previously owned the Micro Black Label DAC/AMP and again really enjoyed the sound from that device. I find that Ifi products seem to have a certain house sound, detailed yet musical and very natural sounding. Was really curious to hear the Go Blu as it uses a different DAC chip to most of their other products.

The box as can be seen is small and compact, comes with the Go Blu, little pouch and a usb to c cable. Instruction card also included

In terms of bluetooth devices similar to this I owned the Fiio Q5 a while ago and although very impressive it did have it's issues for me such as size and some interference when near mobile phone. I also tried the Ifi audio Xdsd, this was a very good device but again a bit larger than what I was looking for in a bluetooth option.

Over the last year I've been trying a few different wireless options and although most are very good they still don't match my wired earphones.
I've been looking for a while at options such as the Fiio BTR5 and the Qudelix 5k. The latter has been more or less impossible to source here in the UK. I've been using a few different USB dongles and settled on the L+P W2 which is a fantastic device with excellent sound quality.

I received the Go Blu in the hope that it might come close to the W2 in terms of sound quality, I knew it wouldn't match my Ibasso DX300 but then that costs around 5 times the price.

Use and impressions

Out of the box the Go Blu is very easy to set up with Android. Paired first time with my Galaxy S21 Ultra handset. Phone settings automatically chose LDAC as preferred codec. On startup the Go Blu has nice little voice to tell you what codecs are available with the connected device.

I've been using the Go Blu with Sennheiser 660s using 4.4mm connection, Fiio FD7 with same connection, I've also sporadically tried Grado Hemp (3.5mm SE), Etymotic er4sr (3.5mm SE) and IMR Elysium (4.4mm)

The Go Blu has plenty of power to drive all of these with no issue, the 660s and Fiio FD7 are my earphones/headphones that benefit most from power, when using the W2 they require volume above the 50% mark to et the best out of them.
Compared to my DX300 they don't get quite the same depth of sound as a more powerful amp section however the Go Blu is no slouch, it competes with the wired W2 in terms of power delivered to the headphones.

From a sound quality perspective the Go Blu is really rather very good at this price point. It retains what I regard as the Ifi house sound, detail is present across the spectrum with what I would describe as a musical textured presentation to the mids. There is detail in the highs but not the sharpness that the W2 has. The W2 probably has slightly better separation to instruments, the W2 also feels a little more set back in the way music is presented, the Go Blu feels like you are closer to the stage (if that makes sense).

From a practical point of view, I've seen a few people feel that a shirt clip should be included, I'm not too bothered either with this, it's not something I would use however can see the benefit.
Lack of an app is another complaint aimed at the Go Blu, again I'm not too worried about this, the Go Blu is a doddle to use and for me doesn't need an app however I can understand that some might like more control over EQ etc.
On the subject of EQ, the Xbass and Xspace work really well, very small subtle changes that just improve certain tracks and albums. Never overpowering though.

Battery life seems good at around 8 hours although I haven't fully run the unit down so not 100% certain on this.

On the whole I have really enjoyed the Go Blu, sound quality is very good, it is easy to use and I can see me using this over wired USB dongles, although it doesn't support sample rates as high as the W2 it is very very close in SQ to the W2 and is some respects I find it more engaging musically.

Slight downsides are that Bluetooth range is not great, often signal start to drop after a few metres, I'd expect a little more but not a deal breaker. Other slight issue is volume control, the volume wheel is really well designed with normal turns controlling volume and the button within controlling track etc however the volume on the phone moves in larger increments than the Go Blu's finer adjustments. Not really a fault of Ifi, more linked to the Android system and again by no means a deal breaker.

Cost is greater than Fiio and others and I haven't heard them to compare however I'd buy the Go Blu, it serves a function very well with excellent sound quality and is also very well constructed.

Build:
The device comes in a nice looking box with both a small USB type-A to type-C cable and a brown Microfiber pouch to carry it. The GO blu is small I was shocked after using portables much larger, it can fit just about anywhere. Its made of a soft material with brushed brass looking accents, in my opinion very handsome looking. It is equipped with both a 3.5mm socket for headphones with a single-ended cable/connector, and a gold-plated 4.4mm Pentaconn output enabling headphones equipped with balanced connectivity to take full advantage of the GO blu’s balanced amp design. In addition, the 3.5mm output benefits from iFi’s S-Balanced circuitry, cutting crosstalk and related distortion in half when used with regular, single-ended headphone connections. The controls are intuitive and quite easy to use. It also features suppoet for a large variety of Bluetooth formats from Qualcomm’s aptX Adaptive and aptX HD, Sony’s LDAC and HWA’s LHDC, regular aptX and aptX Low Latency, AAC (Apple iOS devices) and SBC. The amount of features are plentiful in this little device.

Specs:
Chipset Qualcomm QCC 5100 Series
Inputs Wireless
Wired Bluetooth 5.1 ( AAC, SBC, aptX, aptX HD,
aptX Adaptive, aptX LL, LDAC, LHDC/HWA Codec)
USB-C (24/96)
Headphone Outputs Balanced
SE 4.4mm
3.5mm
Power Output Balanced
SE 245mW @ 32Ω; 5.6v @ 600Ω
165mW @ 32Ω; 2.8v @ 600Ω
Output Impedance Balanced
SE <1Ω
<1Ω
SNR Balanced
SE 111dB(A) @ 0dBFS
116.5dB(A) @ 0dBFS
DNR Balanced/SE >120dB(A)
THD + N Balanced
SE
<0.009% @ (6.5mW/2.0v@600Ω)
<0.03% @ (100mW/1.27v@16Ω)
Frequency Response 20Hz - 45kHz (-3dB)
Battery Lithium-polymer 450mAh approx. ~10 hours
Power System Charging via USB-C, BC V1.2 compliant up to
1000mA charging current and 6.3 volts
Dimensions 54 x 34 x 13 mm
2.1' x 1.3' x 0.5'
Weight 27g (0.95 oz)
Warranty period 12 months

Sound.
Both Wired and wireless you get that signature ifi house sound so neutral with that analog warmish sound, the sound is big and full from such a little thing, its a little impressive. Its somewhere between the Hip-Dac and the Zen's signature in my opinion but very enjoyable to say the least.
Bass is a little north of neutral and lends a pleasant warm but rich detailed Xbass only furthers the Bass punch and depth but in an oh so tasteful way. Mids present neutral with some lower end warmth and forwardness and treble is also neutral and detailed. these of course are dependent on your recording and headphones or earphone your using as well. I tested the GO blu using a few of my favorites. The Philips X2HR, HiFiMan Ananda, Dekoni Blues, Koss Porta Pros. for Headphones and the TIN-HiFi T2 EVO, T2 Plus, Metalure Wave, Sure SE846 PRO, CCA NRA, CSA, QBEYZ Summer and spring, BLON bl03 and 05s, and the KBEAR Believe. I found the GO blu to provide a larger sound to these devices with good layering , soundstage and details. Xspace was very useful to open the sound up even more so and I love its affects when coupled with XBass.



Conclusion:
The ifi GO blu is one of those useful travel must haves it boasts and impressive amount of features and the battery lasts an impressive 10 hours depending on what your using. It connects easy and even the microphone worked great on phone calls. Love this little guy!