[bjd1]

I completely agree. Under-$200 USB-dongles and super-portable DAC/Amps with tiny form-factors (like the one I will compare to in the next paragraph) are a very competitive market, and I don't see how A&K is bringing anything new to the table with this product that other companies haven't already done better than this. Most competing products have a lower output-impedance as many have noted, which means this product limits the use-cases for many IEM's with balanced-armature drivers, despite the fact that the main appeal of a dongle is to have something versatile for both desktop AND portable use. What's the point of portability if it's going to change the sound-signature (probably for the worse) of many hi-fi IEM's? Moreover, yeah this thing doesn't even have a balanced output option (which as you noted should be 2.5mm on a product like this).

Why would I want to pay $150 for this thing when for only $110 I could get a Fiio BTR5 that is nearly as small (and a little USB-C cable for it that'll cost just a few bucks), has less than 1.0 ohm output-impedance, tons of power for such a small device (when I had the BTR5 it could even drive my 120ohm Senn HD560s really well), both 3.5mm and 2.5mm outputs, tons of features including switching filters and a phone-app, at least as many compatibility options, AND a Bluetooth option?

As you say, instead of focusing on making it look cool with a cool shape, they should have focused on giving this thing features that actually compete with similar products from other companies. A&K has always to SOME extent been a company that seems to rely on aesthetics as much as actual sound-quality and features to sell their products, but this little dongle here seems like an extreme case of that trend. If I wanted a DAC/Amp for my smartphone, there are at least ten to twenty products from other companies in this price-range that I would consider before this one. I mean come on, they talk about the 2.0 Vrms output as if that's something actually-special rather than just the industry standard that basically EVERYTHING has now.

Is 2 Ohms output impedance really that high? I thought the rule was “8”, so this should be Ok with headphones of 16 Ohm impedance or higher. Seems to me most IEMs are in the 20-32 range. (But this is coming from someone who’s very happy with the Acmee MF01, which has an output impedance in the low 30’s!)

 

[sabloke]

Can't see how this would best the BTR5 I am using now. If it does, will get one immediately. Sitting on the fence for now.

 

[HiFiHawaii808]

Can't see how this would best the BTR5 I am using now. If it does, will get one immediately. Sitting on the fence for now.

You should try the Lotoo PAW S1. To my ear, it is significantly better than my BTR5. So much so that I rarely use the BTR5 anymore. I ordered a L&P W2 and my understanding is that it might be better than the S1. I'll know next weekend.

 

[bjd1]

Can't see how this would best the BTR5 I am using now. If it does, will get one immediately. Sitting on the fence for now.

This A&K thing might not be the right choice for everyone. But IMHO, the bluetooth dongle DACs are in a different category from the straight USB dongle DACs. I've got several of the Bluetooth types, and when I use them it's clear their primary intended use is over Bluetooth. Yeah, of course you can ignore the Bluetooth and use it as a USB DAC, but there's generally more futzing around required to do that. The big advantage of a USB dongle DAC is that you just plug it in and it works. No holding down buttons to shift it to some other mode, using a phone app to control it, etc. No wondering about its battery status. Just plug it in and listen to the music.

 

[sabloke]

BTR5 works without any drivers having to be installed on my work laptop. Can't install stuff on it anyway. It drives and sounds better that way with my IER-Z1R in ears via a short type-c cable. Very convenient to have music playing from desktop Tidal that pauses when I get a phone call and the dongle switched to the phone Bluetooth connection. Way more power over the balanced port than the AK dongle, too. So tell me again what am I missing here?

It is quite obvious that some are talking about BTR5 without ever holding one in their hand, let alone using it as a DAC.

 

[goodyfresh]

I had the opportunity to listen to PEE51 (USB-C Dual DAC Cable) for more than a week already. So here are some impressions:

• build quality is exceptional, but PEE51 is a bit heavy portable DAC/AMP due to a solid metal shell; cable has additional shield;
• design is simple, yet very impressive IMHO (love it) and there is LED notification of sampling rate;
• from the very first moment, attention is drawn to a very clean sound and a surprisingly dark background, reminiscent of the SR25 model;
• sound is well-balanced, relatively neutral, yet natural and quite smooth in tone, there is good level of transparency with touch of added warmth;
• the lows are dense, tight, detailed and very well controlled, the extension is nice and a small accent guarantees the appropriate mass of the instruments and warms the sound a bit, but the bass does not dominate in any way;
• the midrange is clean and clear with the vocals clearly presented in front of the instruments, the male's does not lack mass; the slightly pushed upper midrange helps to better present female vocals and convey emotions of artists;
• the top end is natural, a touch shiny, but remains smooth and non-fatiguing; it is quite well stretched (with some air in presentation) and the details are there, ;
• nice holography, good width and height, perceptible but not strongly marked depth; resolution, separation and dynamic are good for price;
• generally PEE51 reminds me of the SR25, but with a touch more forward presentation with a tighter bass, while the DAP AK has better depth and touch more refined lower mids; I do not like such comparisons, but PEE51 seems like 70-80% of what the SR25 gives in terms of sound quality (the DAP provide of course higher quality, balanced output, better functionality, but the DAC/AMP is much cheaper);
• PEE51 provides up to 2 Vrms (no load), so it has no problems with IEMs I pair with them (UM MEST/3DT, DUNU Luna/Zen, Kinera Nanna, Moondrop Blessing2, Tralucent 1+X Plus, CA Andromeda, Anew X-One, Aune Jasper);
• great thing about PEE51 is mentioned earlier black background, even with CA Andromeda hiss is minimal.

Some photos:

Interesting, so it sounds like it at least lives up to A&K's claims about performance when it comes to IEM's. I'm curious though as to how it performs with full-sized headphones. These days, there's no shortage of dongles on the market that have a shockingly large output such that they can even power stuff like an HD600 (although not to full potential of course, but much better than one would expect from a tiny dongle), and can power something like my 120ohm HD560s totally fine. I'm interested to know whether this A&K dongle is also capable of such things. If someone wanted to use it as their desktop driver for some full-sized headphones, or for portable use with harder-to-drive closed-back portable headphones like a DT770 Pro, would that be feasible, and would they be able to get anywhere near the full potential of such headphones or would they end up with the typical limp/thin sound that results from too little voltage and/or current?

I'd also be interested to read some direct comparisons to competing dongles from other companies like the ones pictured in the first photo, although I'd be MOST interested to see a purely sound-quality-based comparison with the Fiio BTR5.

No, so you better get a proper phone

Oh DANG, that is HARSH, but honestly I can't disagree with the sentiment when it comes to smartphones for audiophiles specifically

Is 2 Ohms output impedance really that high? I thought the rule was “8”, so this should be Ok with headphones of 16 Ohm impedance or higher. Seems to me most IEMs are in the 20-32 range. (But this is coming from someone who’s very happy with the Acmee MF01, which has an output impedance in the low 30’s!)

The issue is mostly with IEM's. While almost all have a LISTED impedance of 16ohms or higher, their actual impedance-graphs usually have large dips/peaks across the frequency-range. This is especially common in IEM's with multiple balanced-armature drivers, which can sometimes dip to impedance-levels as low as 8ohms or even 5ohms at certain frequencies. A 2ohm output impedance can very much have a negative impact on the tonality of IEM's in parts of the FR where the impedance dips. Impedance is NEVER CONSTANT, and the listed number on headphone or IEM specs is generally just some kind of baseline or average, with no info given on peaks/dips.

The Acmee MF01, with its extremely high impedance, almost certainly bloats the bass and low-mids, and possibly has other, stranger effects on various aspects of the sound, on various IEM's and headphones used with it, unless you're exclusively using full-sized headphones with very high impedance (250 ohms or higher).

Can't see how this would best the BTR5 I am using now. If it does, will get one immediately. Sitting on the fence for now.

I highly doubt it. I had a BTR5 for a while (I ended up returning it because I couldn't get the Bluetooth to stop lagging on videos in Windows, which is a Windows issue not a BTR5 issue but still made it not worthwhile for me, and because I decided I wanted more power and didn't need the portability) and for what it is, it's INCREDIBLE. It's so feature-packed for only $110 that it's practically unbelievable, the sound is excellent beyond what anyone would expect at that price-point with so many features, and even without balanced output it proved MORE than powerful enough to drive headphones like my HD560s (120ohm impedance, 99dB/mW sensitivity) very, very well. Although my current Fiio K5 Pro of course drives the HD560s even better, the Fiio BTR5 came much closer to the performance of the K5 Pro with these headphones than anyone would ever expect from it. And it did an AMAZING job with my IEM's, driving them to their absolute full potential. If you want basically every possible feature (switchable gain-modes, small form-factor, a battery with a long life, great sound, unbelievable power for such a small device, a balanced output, switchable filters, great volume-control, a phone-app to control it, AND bluetooth-capability), then the BTR5 seems to be just about the best product currently available in this category (teeny-tiny little portable USB-powered options). Even fi you DON'T need ALL those features, the BTR5 still blows just about all other similar-sized products in the under-$200 price-range right out of the water. I don't see how other companies can really even hope to compete with it.

 

[sabloke]

So let me get this right. The AK dongle has no LDAC or any other Bluetooth capability, no battery, no balanced port while costing over 25% more than one of the current segment leaders, BTR5. Its sound quality better be amazing then! Can't see much point launching it without wireless capability but then I'll reserve my judgement until we can listen to it.

Who wants to bet Chord might be launching their dongle next?

 

[goodyfresh]

This A&K thing might not be the right choice for everyone. But IMHO, the bluetooth dongle DACs are in a different category from the straight USB dongle DACs. I've got several of the Bluetooth types, and when I use them it's clear their primary intended use is over Bluetooth. Yeah, of course you can ignore the Bluetooth and use it as a USB DAC, but there's generally more futzing around required to do that. The big advantage of a USB dongle DAC is that you just plug it in and it works. No holding down buttons to shift it to some other mode, using a phone app to control it, etc. No wondering about its battery status. Just plug it in and listen to the music.

The BTR5 is SHOCKINGLY convenient and easy to use, fully capable of just plug-and-play although you can control it more from your computer if you install Fiio's USB DAC driver (which is easy to do). When I had my BTR5 in the past, I had it playing music as a USB DAC within literally seconds of plugging it in to my laptop. It also has its own volume-control right there on the device that works in USB-mode, and you can also control the gain, switch filters, etc., without the phone-app, all while still plugged in and running from USB. And Fiio has made it as a product that does sound great with Bluetooth, but sounds AWESOME (for its price) as a USB-DAC/Amp. It is CERTAINLY not true that its primary intended use is Bluetooth, everything about using it gives the impression that it's EQUALLY intended for both Bluetooth and USB-Mode.

It is quite obvious that some are talking about BTR5 without ever holding one in their hand, let alone using it as a DAC.

Heh, exactly. While I myself returned the BTR5 because I decided I didn't need the portability, wanted more future-proof power-output, and couldn't get rid of Bluetooth latency in Windows (which is entirely a Windows issue, not a Fiio issue), the fact is that I have nothing but praises to sing of that amazing little device as both a USB-DAC and as a Bluetooth receiver. The BTR5 is essentially the ultimate pinnacle of all products of its type. I'd actually call it amazing for its price even if it didn't have Bluetooth.

At a cost of $40 more and without all the features, what does this new A&K product offer (other than being smaller, but the BTR5 is itself plenty tiny) that would make it a better purchase than the BTR5? The only thing I could think of would be if the A&K dongle has much, much better sound quality, but is that even possible for products this small? BETTER sound-quality than the BTR5 should be possible (someone above says the Lotoo PAW S1 sound better than the BTR5, and I don't doubt them, but it's worth noting that the Lotoo is 150% of the price of the BTR5), but MUCH better seems like a stretch with current technology, and the A&K dongle uses a comparatively outdated DAC chip. And even if it somehow does have far better SQ due to a very good amp-circuit (I'm not saying it's ENTIRELY impossible the A&K has far better SQ, I'd be interested in a direct comparison), what's necessarily the point when it has twice the impedance (too much for many multi-B.A. IEM's) and no balanced output like the BTR5 has?

 

[HiFiHawaii808]

BTR5 works without any drivers having to be installed on my work laptop. Can't install stuff on it anyway. It drives and sounds better that way with my IER-Z1R in ears via a short type-c cable. Very convenient to have music playing from desktop Tidal that pauses when I get a phone call and the dongle switched to the phone Bluetooth connection. Way more power over the balanced port than the AK dongle, too. So tell me again what am I missing here?

It is quite obvious that some are talking about BTR5 without ever holding one in their hand, let alone using it as a DAC.

Since I own a BTR5 and used it extensively, you wouldn't be talking about me. I also own the Sony IER-Z1R and I can tell you that the BTR5 does not come close to allowing you to realize the full potential of those IEMs. You may love the sound you are getting, but it gets a lot better. I find the Lotoo PAW S1 superior to the BTR5 and I expect the LPW2 to be even better. I'll know by next weekend. I am interested in the A&K dongle to see if I like their sound signature for potentially purchasing a DAP. That is it's real purpose. Not to be a be all and end all for end customers.

Since there is no side tone on the BTR5 allowing you to hear your own voice while talking, the sound quality for voice calls leaves a lot to be desired. It's intolerable to my ear. I prefer carrying a second headset in my Airpods Pro and switching to those by taking out my IEMs to talk on the phone.

 

[sabloke]

I can tell you that the BTR5 does not come close to allowing you to realize the full potential of those IEMs.

Nor will the AK dongle, for sure. I don't expect the best out for my IEMs with a $100 Bluetooth dongle, to be clear. It's just that for what I need, some background music or YouTube videos while at the office, commuting or walking the dog, something like BTR5 is plenty good enough. Sold my M11 Pro last week as it wasn't being used at all since got the BTR5. At home I have a proper desktop setup to get the most of my IEMs and headphones.

One more thing: a wired device is nowhere near as convenient on the go as an LDAC capable device. One wrong move and a wired dongle will get you to tears when it bangs into that nice 6.7" OLED screen and cracks it

 

[goodyfresh]

Since I own a BTR5 and used it extensively, you wouldn't be talking about me. I also own the Sony IER-Z1R and I can tell you that the BTR5 does not come close to allowing you to realize the full potential of those IEMs. You may love the sound you are getting, but it gets a lot better. I find the Lotoo PAW S1 superior to the BTR5 and I expect the LPW2 to be even better. I'll know by next weekend. I am interested in the A&K dongle to see if I like their sound signature for potentially purchasing a DAP. That is it's real purpose. Not to be a be all and end all for end customers.

Since there is no side tone on the BTR5 allowing you to hear your own voice while talking, the sound quality for voice calls leaves a lot to be desired. It's intolerable to my ear. I prefer carrying a second headset in my Airpods Pro and switching to those by taking out my IEMs to talk on the phone.

At $165, the Lotoo PAW S1 is 50% more expensive than the BTR5, but I'd still say it's close enough in price to be a valid comparison, so I'm definitely intrigued by your claim of it sounding better than the BTR5, and would be interested in the chance to compare them someday. The L&P W2 is around $300 though, so it wouldn't be fair to compare it to either the BTR5 or to the new A&K dongle.

If I ever decide I want a portable option other than my trusty old Hiby R3 DAP and am able to upgrade to pricier IEM's (right now I use the Fiio FH3), I may consider the Lotoo, the L&P, or the new A&K if it turns out to have better SQ, instead of the BTR5. But that won't be for a while, if ever.

The BTR5 was able to bring out the full potential of my IEM's and a lot of the potential of my full-sized cans (X2HR, HD560s), but then again my IEM's and headphones are all mid-fi priced, nothing like your summit-fi $1700 Sonys, haha. I don't doubt you at all that the BTR5 probably can't bring out the full-potential of over-$1000 summit-fi IEM's

 

[zolyniakm]

@goodyfresh vs FiiO BTR5? Ok, here (FiiO as USB DAC/AMP; both from PC):
- AK PEE51 has a cleaner sound with noticable darker background and protection against EMI/RFI is better (much less hiss when using near smartphone working on 4G);
- the sound of PEE51 has better control, is more natural and with higher level of transparency; BTR5 sound is more digital, with more obvious coloration;
- PEE51 has a more textured lows, denser, yet well controlled, with better extension into subbass; microdynamic is better with AK, but overall level of macrodynamic depends on paired IEMs;
- the mids of PEE51 are smoother, with more focus on better rendered vocals; BTR5 has clearer, sharper mids with touch better separation within "X" axis;
- the highs are a bit boosted with BTR5 that cause it to sound way less natural; the level of details is nearly the same, but FiiO has a touch more resolution;
- the soundstage width is better with FiiO, PEE51 has better height, depth is similiar (not very impressive on both); stage with AK has more 3D-feel and PEE51 work better with imaging and showing correct position of instruments.

FiiO BTR5 is a good product, but I don't find it to be spectacular or something worth flexing. Maybe with darker sounding IEMs it could be good option, but otherwise anyday I'm choosing PEE51. The best for you is to compare both and choose one you like better.

 

[goodyfresh]

@goodyfresh vs FiiO BTR5? Ok, here (FiiO as USB DAC/AMP; both from PC):
- AK PEE51 has a cleaner sound with noticable darker background and protection against EMI/RFI is better (much less hiss when using near smartphone working on 4G);
- the sound of PEE51 has better control, is more natural and with higher level of transparency; BTR5 sound is more digital, with more obvious coloration;
- PEE51 has a more textured lows, denser, yet well controlled, with better extension into subbass; microdynamic is better with AK, but overall level of macrodynamic depends on paired IEMs;
- the mids of PEE51 are smoother, with more focus on better rendered vocals; BTR5 has clearer, sharper mids with touch better separation within "X" axis;
- the highs are a bit boosted with BTR5 that cause it to sound way less natural; the level of details is nearly the same, but FiiO has a touch more resolution;
- the soundstage width is better with FiiO, PEE51 has better height, depth is similiar (not very impressive on both); stage with AK has more 3D-feel and PEE51 work better with imaging and showing correct position of instruments.

FiiO BTR5 is a good product, but I don't find it to be spectacular or something worth flexing. Maybe with darker sounding IEMs it could be good option, but otherwise anyday I'm choosing PEE51. The best for you is to compare both and choose one you like better.

Interesting! So it DOES sound a good deal better, good to know. So what about comparisons to other competing products like the Lotoo PAW S1?

 

[zolyniakm]

@goodyfresh no problem, here vs Lotoo PAW S1 (both from PC):
- LPS1 is more natural here with more transparent mids and more liquid-like presentation; PEE51 in comparison sound touch more neutral, so it could sound more "technical" (not as natural and effortless);
- PEE51 provides tighter and a bit faster lows; PAW S1 has touch loosen bas, but not much boosted; there is also good control with more impact and greater extension with Lotoo (a bit more noticable with 4,4 mm balanced output);
- PAW S1 has smoother, more transparent, yet just touch more detailed mids; PEE51 provide clearer mids, quite smooth, but more neutral and with touch more separation; instruments sound fuller with PAW S1, PEE51 on the other hand show more focus on vocals;
- both have similiar extension into highs, but PAW S1 is here more natural/smoother; PEE51 shows jus a touch more sparkles;
- PAW S1 is noticable bigger sounding device, windth is nearly at the same level with 3,5 mm (SE) and wider with 4,4 mm (bal) with LPS1; both outputs has better depth and height that PEE51.
- PEE51 sound a touch cleaner, both have dark background, yet AK is less affected by EMI/RFI.

Of course, PAW S1 come with 3,5 mm/4,4 mm, option to work with iPhones, hardware volume control, OLED screen, PMEQ II/ATE effects (if someone want to use them) and adapter USB-C to USB-A in box.

 

[ljnew]

I had the opportunity to listen to PEE51 (USB-C Dual DAC Cable) for more than a week already. So here are some impressions:

• build quality is exceptional, but PEE51 is a bit heavy portable DAC/AMP due to a solid metal shell; cable has additional shield;
• design is simple, yet very impressive IMHO (love it) and there is LED notification of sampling rate;
• from the very first moment, attention is drawn to a very clean sound and a surprisingly dark background, reminiscent of the SR25 model;
• sound is well-balanced, relatively neutral, yet natural and quite smooth in tone, there is good level of transparency with touch of added warmth;
• the lows are dense, tight, detailed and very well controlled, the extension is nice and a small accent guarantees the appropriate mass of the instruments and warms the sound a bit, but the bass does not dominate in any way;
• the midrange is clean and clear with the vocals clearly presented in front of the instruments, the male's does not lack mass; the slightly pushed upper midrange helps to better present female vocals and convey emotions of artists;
• the top end is natural, a touch shiny, but remains smooth and non-fatiguing; it is quite well stretched (with some air in presentation) and the details are there, ;
• nice holography, good width and height, perceptible but not strongly marked depth; resolution, separation and dynamic are good for price;
• generally PEE51 reminds me of the SR25, but with a touch more forward presentation with a tighter bass, while the DAP AK has better depth and touch more refined lower mids; I do not like such comparisons, but PEE51 seems like 70-80% of what the SR25 gives in terms of sound quality (the DAP provide of course higher quality, balanced output, better functionality, but the DAC/AMP is much cheaper);
• PEE51 provides up to 2 Vrms (no load), so it has no problems with IEMs I pair with them (UM MEST/3DT, DUNU Luna/Zen, Kinera Nanna, Moondrop Blessing2, Tralucent 1+X Plus, CA Andromeda, Anew X-One, Aune Jasper);
• great thing about PEE51 is mentioned earlier black background, even with CA Andromeda hiss is minimal.

Some photos:

How does the sound compare to lg v series?