Reviews by Voxata


Headphoneus Supremus
NITSCH x Schiit Pietus Maximus
Pros: Excellent sonic experience with an engaging and fatigue free experience
Cons: Only SE
NITSCH x Schiit Pietus Maximus Review:

Today I’ll be sharing my experiences with the NITSCH x Schiit Pietus Maximus paired with my headphone and DAC stable. I was fortunate enough to be able to purchase this DAC slightly before release and am choosing to share my impressions of my own decision. I’m not being compensated in any way for this review and as always, my viewpoint will be unfiltered. My preferences may be different from yours and I welcome this.

My review chain is as follows: Schiit Modi Multibit 1, Modi Multibit 2, Bifrost 2 OG, Gungnir A1, Modius E. Yes, my DAC collection is pretty Schitty. I’ve also owned the Gustard R26, Yggy A1/2/LIM and several other high performing DS and MB dacs. Headphones are JAR580 OG & HD8XX EQ'd


This is extremely important as synergy is king in the world of audio enjoyment. I found that the Modi Multibit 1 and by similar sonic extension the built in MMB card are an ideal match for my preferences. The BF2 OG sounded good, Gungnir SE wasn’t as great due to the inherent limitations of that DACs SE outputs. MMB2 was serviceable but not as layered as MMB1, MMB2 is a touch energetic in the treble and Pietus revealed this. Modius E was another excellent pairing and, as before by extension the built-in Sabre card will also perform well here.

So, long story short you won’t need an uber-buck DAC to get great sound of the Pietus. A neutral/dark one is a great match. Just get yourself one of the in-built DAC cards from either Nitsch or Schiit and call it a day with an all-in-one solution or get yourself a used MMB1/Modius E for pretty cheap. They are all over and reliable.

For headphones I use primarily the JAR580 OG (which performs similar to the JAR600 available on NITSCH’s website) and an EQ’d HD8XX. The 660S/S2’s were also great from this amp. I don’t currently own any Planars so if this is your primary headphone type I won’t be able to share any impressions, however given the specs of this amp it should perform well enough with everything short of the HE-6. I can certainly say that the Sennheisers I own sounded incredible. The JAR series in particular really did shine on the Pietus.


Features and Operation:

This amp is simple, RCA in and SE out with an RCA out pre section as well. Inside is an Alps RK27 pot which I have absolutely no complaints about. The black knob on the front is a very welcome change from the usual Schiit gray affair. Everything feels smooth and there is no annoying light up front, though the power switch is still in the back per classic Schiit design. In the front there is a three-pole gain selector which is -10db, 0db and +15db. Unlike the original Piety the gain settings are perfect and even high gain allows for some pot movement before ramping up quickly. Power is rated at 4.2w into 32ohms and 600mw into 300 – which is to say plenty. Internal PCB is white and components are very high quality. Add-in cards are supported of course making this a compelling all-in-one solution. The Pietus also runs pretty cool and can be left on 24/7 without worry. This is a big plus in my opinion.

Sound Quality:

Compared to the Piety the Pietus is not as upper mid forward – which is quite the relief. Depending on the headphones (looking at you, 660S) this posed quite the problem with Pietus’s little brother. With the other 6 series I had no qualms. Pietus has a more relaxed and fleshed out low-end as well with a very organic bass presentation. My favorite rendition of the lower registers was from the Modi Multibit DAC (or MMB card) as the heft was very engaging and the high frequencies are smoother as well. Perfect match for the 600 series. Modius E wasn’t far behind trading a bit of euphony for accuracy and speed, which the higher tier headphones took advantage of. Midrange here is incredibly resolving from Pietus, not to be confused with overly sharp or detailed. Every sound is complete with a pleasing finish and my urge to keep playing tracks definitely overwhelmed. Treble range is a huge improvement with Pietus. It is far more detailed and engaging than the Piety, as well as more even. This is as far as my subjective FR analysis will go, but I will say that Piety is punchier on the top and bottom while Pietus has the far and away more elegant and performant midrange – all while having more cohesive bass/treble capabilities.

My initial approach was going to be comparing the Pietus to other amps in my stable and really digging down deep. This plan quickly faded away upon long listening sessions with the Pietus. All sounds were distinct and had a great follow-through. Like a craft brewed coffee finish on my pallet, Pietus was nimble in how it carved through my music library presenting music in a different way that really won me over. This isn’t your typical measurement focused amp yet doesn’t present itself in a way that is deficient either. I’ve spent a lot of time comparing gear and using music I know as a tool. The Pietus just made me want to listen and enjoy for hours on end, which is what this hobby is supposed to be about. Soundstage isn’t the biggest I’ve heard; however, the mid-sized staging has incredible resolve and cohesion – on top of accurate placement. Nothing is missing or obscured. Incredibly engaging and textured throughout is how I'd characterize the Pietus.


Simply put Pietus is the best sounding SS amp I’ve ever heard (I've owned the Auralic Taurus MKii, Rag 1.5&2, GS-X Mini and many more) and suits my preferences well. It’s effortless in presentation and I don’t even care to analyze my music while using it. It runs cool and presents my music in a way that wants to be heard and enjoyed. It finds that perfect balance between performance, engagement and a very slight euphonic touch. It’s not flat or panned, wide or claustrophobic. Honestly it brings me back to the roots of what I enjoyed about this hobby in the first place every time I listen to it.

As an aside I was considering giving MJ3 a go using Schiit’s 15-day trial. However the Pietus has left me quite pleased, even surprised. I think I’m good here, and it’s time to get back to listening. Thanks for reading all!

Again, the nice white PCB of the Pietus:

Couldn't agree more, great review. The Pietus deserves more love. Others will catch on soon enough to what a sleeper this guy is.
The MJ3 is the ultimate comparison for $$$ and FOMO X'D. I went the other route, heard the MJ3 and have not heard the Max yet (I have a Piety/SA-1/Valhalla 2). Great collection of Schiity DAC's! Will you be tempted to try a MIB/LIM? If I get back to the Schiitr I'll try and see if I can't buy one of the BF2 OG's collecting dust as decorations on the shelves (by my count they have at least 3 of em, don't know if they're operational or not)
I really like the BF2 OG with this as well, great pairing. Not a huge fan of LIM, have not heard MIB. LIM is nice don't get me wrong but, for headphone use BF2 OG is my all around favorite. Also, I've had the SA-1 and Pietus has just taken over for everything. A+ amp!


Headphoneus Supremus
A strong refresh that ends up just missing the mark
Pros: Macro capability, Unison USB-C, No SPDIF audio delay
Cons: Can be a sidegrade to older modded Bifrost/Modi Multibits sonically depending on classic/modern Schiit sound preference
First off I'd like to thank my wife, for allowing me to buy more audio crap I probably don't need. This review will be more of a quick rundown of how I feel about the MMB2 as opposed to a full on review.

With that out of the way let's talk about the Modi Multibit 2, which I'll be referring to as the MMB2. This is a refresh of the very long running Modi Multibit which really brought a lot of attention to Schiit when introduced. It offered a similar sound to the Bifrost MB at a fraction of the price and size. Those with hopes this will be a repeat of that release will be sorely disappointed. The MMB2 unfortunately does not reach for the performance of Bifrost 2/64, it reaches in a different direction than even the MMB1 despite using the same chip at heart. Still a successful DAC, just not to the level of it's predecessor.

MMB2's sound characteristics could be described as having stronger macro than micro. The DAC has a bit of a dark tilt yet still has an up front sound. The bass is very plentiful and engaging yet a little loose at the same time. It also doesn't slam extremely hard at the lowest octave but is pleasing in what it has, which helps limit fatigue with some listeners. This could also be good for some pairings. Mids are clear and reserved, though not recessed. The treble sees a significant improvement over the MMB1 as it is extended, engaging and decently quick. It has a bit of a D/S presentation in some ways that I find enjoyable given the rest of the spectrum. For the money the MMB2 absolutely performs admirably.

My biggest complaint with MMB2 has to do with staging. Placement is different than I'm used to with the original BF, B2/64 or Gungnir. Instruments are brought inward but there is a nice warmth throughout. Layering suffers some because of this. This presentation works well with Jot2 and was quite enjoyable, however with Piety I had to stick to brighter headphones so be sure to pair accordingly. I'd wager this would be a great pairing with the new Magni+.

A huge improvement is the SPDIF performance on the MMB2. The delay on the BF2 made it unusable for home theater or gaming - and I had to stick to using USB. Not so with the MMB2, no delay whatsoever! This is refreshing as it is the only thing about BF2 that really annoyed me.

Right now I think the BF2 is the best DAC in Schiit's lineup when both capability and price are considered. I had hoped MMB2 would take that crown, however it only takes the crown from the original MMB. While it seems I may be ragging on the MMB2, the reality is that MMB2 is still a great DAC. It just doesn't reach the heights the original expectations the MMB set. Despite being better than it in most ways.
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Huh… surprised you like the MMB2, yet sold off the BF2 so quick… doesn’t seem to make much sense…
hi, is the B2/64 good pairing with the Piety? or should i look for a used Bifrost2, or do you suggest other dac? 😊 thx
Both pair nicely, so you may dabble here. Used BF2 OGs can be had really cheap.


Headphoneus Supremus
Questyle M15 - Proving Questyle is back
Pros: Sound quality, size, efficiency, power, staging/layering
Cons: Gain switch difficult to access when inside of the case, can be a good thing though for no pocket sound surprises.
Questyle M15 - This review is going to be a stream of thoughts and impressions. I hope you enjoy.

Today on my desk I've got the Questyle M15. The M15 at this point has a strong following and I've been determined to see if that following would stand up past the initial release hype. Questyle has promised a full CMA implementation in this tiny dongle with power consumption and running temps that are in check - we'll see if they have held up to that goal in this review.

Before receiving the device I did what any sane person would do - research and assume, right? On their website Questyle has marketed this as having incredibly low distortion, to the tune of 0.000X% and beyond. Inside is a capable ES9281Pro DAC chip that hands off the signal to their new current mode amplification SiP modules. I'll be honest I'm a bit in the middle on if I'm a fan of Sabre. I have heard DACs flat as a board with enough pierce in the treble to give me a headache before the first song is over. The Fifteen from Questyle is the first later revision Sabre chipset I've heard that has completely transformed my impressions of Sabre largely thanks to the CMA output stage.


Given this experience, I had high hopes for the M15. I was a bit worried when I read the power specs however. For some reason it is measured on their site at 300ohms. The M15 supposedly puts out 11.97mW on the 3.5mm output and 22.60mW on 4.4mm. Once I received the dongle in though I believe numbers are so incredibly conservative it isn't even funny. With my AKG K712 I am sitting at 23 OS volume in low gain with Foobar playing at -18dB attenuation. This is my upper threshold of what I can handle for routine listening. This dongle is an absolute powerhouse. Switching over to my modded HD650 I could only nudge Foobar to -16dB! This performance proved the M15 is more than capable of driving anything I own, either IEM or full size power hungry headphones.

When listening to the M15 and switching to IEMs one has to be careful. I dropped the volume to the floor when switching over to IEMs and creeped up from there. It seemed that from my phone the power was a touch more conservative (still plenty of it though) and my PC was capable of feeding it even more. So, this gives me confidence Questyle has power management in check on this little device.

Also very important to note is that the running temperatures on the M15 are crazy good. It barely gets warm to the touch, even attached to my desktop PC. The new CMA SiP modules are an engineering feat to have such power. Very akin to THX design however sans the sterility in sound, but more on that later. In my pocket the M15 was completely unnoticeable. Questyle was on a mission with this dongle I believe. Size, power, sound and efficiency. The size to me makes the lack of internal battery or wireless connectivity a non issue. The sound from the M15 blows every wireless device I've ever tried out of the water, enough to sate my old school belief of 'wired of always better' anyways.

My mobile testing consisted of my trusty OnePlus 7T and as a mobile platform the M15 exceeded my expectations. I had no dropouts, stuttering or sync issues. I also did not encounter any EMI noise - which given that one side is glass I suspected the M15 may have been impacted. No issues, though given it is a dongle I'd have rather had the choice to either have a removable metal plate over the glass or just not a glass side at all. It has taken a few good thwacks in my pocket though, so whatever they are using is rather robust. There is a nice leather case for it available through Questyle as well in several colors. It does allow for some nice visibility through the glass of the status lights within. These notify you of different rates and connectivity/power. Let's move on.

(The size of the M15 is incredible)


I figured I'd just use the M15 as a convenient portable for LAN events and on the go. Definitely for downtime at work. The M15 has proven to me that it can fulfill those roles, however it went a step further. It completely replaced my desktop setup for gaming. The M15 is accurate, incredibly so. When testing with Hunt: Showdown which features binaural audio I was greeted with a boundless soundstage with excellent layering. Bass was in check yet present and engaging. Treble was not so explosive that it was uncomfortable and the midrange is so smooth without losing detail. It is also very clear. Even better though, it was resolving beyond even some of my desktop gear. Decay is incredibly detailed and natural so the sound doesn't come off as either too warm nor too sterile. The negative feedback gear I've owned previously (think THX, Topping, etc) has a habit of squashing the sound and compressing the stage with a very 'wall of sound' effect in this game. This capability was very unexpected from the M15.

When it comes to music the M15 performed incredibly well here as well. I've got some state of the art desktop gear and for a dongle not to embarrass itself in the slightest is a huge testament to the engineering that went into it. With my setups each has a specific pairing it excels at. The Fifteen dominates with my AKG K712/HD660S with the BF2/J2 coming through with a different flavor for these headphones. LIM/Rag2 lights up my Sennheisers and my LS50 speakers. Mixed up, each of these systems looses their engaging synergy and in case of the AKG K712/LIM/Rag2 setup becomes harsh. With the M15 I experienced an enjoyable listen through everything I connected to it. Was it on the level of Schiit gear with an HD650? No.. Was it a lesser match like other pairings I've got? Not at all. Same can be said when arranged the other way. When listening to the M15 for extended periods I didn't outright miss my other desktop gear, which is the highest praise I've given any portable.

As far as putting a pin on the sound I'd call it detailed yet natural. The resolving capability from this DAC puts it well ahead of any competing gear in the same price range. A competing Schiit stack would have to be over the 1K mark and still doesn't perform as admirable with every headphone/IEM I've thrown at it. When a key pairing hits it can absolutely be better, but the M15 itself doesn't seem to care what you connect to it. Everything sounds great. The Bass performance from the M15 goes deep and is very engaging. It takes the HD650 as low as it will go and the AKG K712 even further with a strong but not overwhelming presence. It is also fleshed out. Male vocals are engaging with have weight and authority. Midrange is incredibly resolved and the treble has sparkle that doesn't overwhelm. There is no thin sound from this dongle, which cannot be said for much of the competition I've heard (here is to looking at you, FiiO...sorry)

There is one gripe I do have about this device though, and that is when connected to a PC that gets turned off I needed to unplug and replug the headphone cable to get the M15 to 'wake up' and be seen again. I'm assuming this could be altered in the firmware, I'm using Windows 11. It could also be a standby power setting on my system that is causing this and it isn't a huge deal. I don't think it was designed to be a desktop device at all yet it really is competing in that realm. With these new modules I really hope Questyle puts out a USB powered desktop Dac/Amp. There would absolutely be no competition in this segment if the performance exceeds the M15.

As far as portable comparisons I can comfortably say the M15 has outperformed everything I've heard and owned. It is more layered than the iDSD Gryphon - and somehow more usably powerful despite the Gryphon's specs. The Gryphon had some compression in the lower registers that put me off. Where the Gryphon exceeds the M15 is capability of features and compatibility. FiiO BTR series? Not even close when it comes to sound quality however it IS wireless. iDSD BL/Signature? Not neutral in any sense of the word but I would say the bass is more engaging, given it's added coloration. The Sig/BL soundstage has a three blob thing going on and it definitely lacks the M15's resolving capabilities. I struggle to point out a specific weakness with the M15 while it puts a performance in each metric that could be considered solidly very good.

I've not much else to add on the M15, aside from that the praise it has received since launch is absolutely warranted. Many of these have sold and the thread is active, yet I've not seen many used units for sale. I'm observant of these things as it sends up a possible flag of hype in my hunt for great audio. Anyways, thanks for sticking around for this long and I wish all my readers the best. Jam on!
White Hat Bob
White Hat Bob
I have the BTR7. I have compared the Earmen Collibri, which has the same ES9281Pro and ESS SABRE PRO chips as the M15, with the BTR7, which has the ES9219C and THXAAA-28 chips, and the Collibri definitely sounds better than the BTR7, so it's safe to assume the M15 will also likely sound better than the BTR7. The BTR7 has a nice implementation of a mini-screen, Bluetooth, nascent EQ, a connected app. etc, but the sound is meh, especially when using Bluetooth. The Collibri has none of that but has a great case (with a belt clip which the BTR7 case does not have), separate USB-C and Data ports (which help it sound so good), a 5-hour battery, and a button/case/balanced 4.4 mm pentaconn configuration with strong output that is great for walking/running. If I didn't already have the Collibri, I'd definitely take the M15 over the BTR7 even though I'm a FiiO fan (Love my FiiO M11 Plus ESS DAP).
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Thanks for this info White Hat! I'm not a huge fan of the THX sound on mobile devices I've tried. I think the Questyle amp circuit used here has a ton to offer. I hope you get to try the M15, it is priced really well for the performance.
Great review!!
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Headphoneus Supremus
Aune X1s GT - The perfect DAC/Amp for the 99%
Pros: Tonality, engagement, input/output capability
Cons: Finish easily marked though it rubs off
Aune X1s GT
The original Aune X1 was introduced over 11 years ago. Think about that, 11 years! Upon it’s release the X1 quickly became a fan favorite. It provided a strong Dac/Amp combination performance and to this day there are a huge amount of these in circulation. They’ve proven reliable, they sound great and Aune is still selling them well. With the Aune X1s GT we’re entering the 8th generation of this product. While from a glance each generation has shared the same shape internally there have been massive upgrades and complete redesigns over the years.

As a disclaimer I have no financial incentive or ties to Aune. This is the first product I’ve tried from them and I am not being compensated in any way for a positive review. I won’t pull any punches here. This unit has been toured and was also taken to a local Denver Head-Fi member meet with positive reception, I’ll lightly touch on some of those impressions below.

Fit, Finish & I/O:

For a low $300 product we’re looking at a pretty versatile all in one device. The Aune X1s GT has the ability to function as a DAC, Pre and fully balanced headphone amplifier which is above many other options in this price bracket. Starting with the rear of the X1s GT we’ve got both fixed and preamp out. I really like this design because I can control my monitors and also a secondary headphone amplifier if I want to share my music with someone else in the room or just try another amp. Not having to unplug and replug cables to accomlish this is is rather convenient.

Digital inputs are three in total. Optical, Coax SPDIF and USB. Additionally there is an additional input for an optional clock controller offered by Aune. Unfortunately, I do not have this clock on hand however, for a budget piece to have external clocking capability is a welcome surprise.


On the front of the X1s GT we’ve got an input cycle button that doubles as filter selection when double pressed – more on that feature later. We’ve also got the usual ¼ plug and a very welcome addition of a truly balanced 4.4 socket pushing out a healthy 1.2 watts per channel. Given the size of the unit standard XLR was not feasible however I prefer 4.4 myself as it’s such a sturdy connector. Aune also has a surprisingly high quality 4.4 to 4XLR adapter cable for near what the parts would cost to build it yourself, if needed.

When in use the potentiometer has an inviting red glow ring around it. My son was a big fan of this as it matched his gaming PC and made for a really pleasing aesthetic. Controlling volume for the X1s GT is an ALPS pot, I'm glad they avoided going digital control. Balance was fantastic through the usable volume range. The knob itself feels smooth and has great grip. I really like the notch and marker as it's easy to see in various lighting conditions especially due to the surround glow.

Finally, the X1s GT is housed in a solid piece of metal and is a very weighty unit for the size. One problem I have with smaller DACs or amps is with the unit sliding and tilting when plugging in or even when just adjusting the volume. The X1s GT stayed firmly in place throughout use even with all connectors in place on the rear.


Sound Quality:

When demoing the Aune X1s GT it’s easy to be distracted by it's size. Maybe we've all grown accustomed to the bigger is better mantra. At our local meet I went as far to tell users jokingly to just put up their hand to cover the unit from sight and just take in the sound. Despite it's visually compact first impression the X1s GT packs a serious punch from the balanced output. While the 1/4 lacks the significant power of the balanced socket it still retails the sound quality. When listening to the HD650 I was about 65% on the volume pot when using single ended, so it's not lacking or unusable by any means. Balanced just has a lot of current.

Perceived sound quality between the two outputs was undetectable for me.
I feel the auditory performance of the X1s GT is rather exceptional for the price bracket. Compared to my Jotunheim 2/Modius the X1s GT was far more focused. Bass is tighter and more 'true'. It's far less overwhelming. Authority without eggaguration. With Modius/J2 the dynamics can also be exaggerated and rather shouty. The X1s proved to be far more comfortable for longer listening while still retaining a strong sense of engagement. In this comparison it also doesn’t hurt that the X1s GT sports a much lower price point.

Compared to the Questyle CMA Fifteen the DAC section in the X1s GT is surprisingly competent. The tonality was largely similar from single ended while the technical performance of the Fifteen pulled ahead with it's 9038 Pro chip. When comparing them both as all in ones the Fifteen presented a larger soundstage with a more definined outline between instruments. Further improvements were present throughout the frequency range, as they should be for a flagship product however my positive impression always came back to the X1s GT's sharing of the same tonality. While it may lack the 'grand' presentation of the Fifteen I don't feel like I'm being short changed when I enjoy the X1s GT. It has an inviting sound that is either musical or detailed when called upon to do so.

I like to think of the X1s GT as a DAC/Amp combo that is suitable for any use. It absolutely excels at both gaming and music. This is something I’ve always had to use two setups for. I’d have a stack for music and one for gaming. With the X1s GT for the past few months I've been more prone to just turning one unit on and be ready for whatever I'm doing at my desk.

As far as perceived FR goes the bass is fast and crisp while still having an engaging thump thanks to it’s class A circuitry. The bass has a bit of warmth and great engagement factor. Mids are present but not overpowering, clear and mature thanks in part to the Sabre chipset. The sound is ever so slightly smooth so that the detail isn't overdone becoming eventually grating like in some units I've reviewed that have come from China recently. Highs are very smooth on the X1s GT and long term listening fatigue is very much on the low end. In my planars when the treble hits right the sound is instantly engaging and really gets my attention in a good way with great sparkle. The X1s's sound performance ticks so many boxes for me.

In terms of filters there is a Standard one for General & headphone use as well as Pure with the same set. Pure I believe lacks any shelfing – I preferred standard headphone for my K712's and Pure for HD650. The standard filter sounded great on my monitors. The best part about these filters though is that they were audibly different. Depending on what I tried I may prefer a different filter. Careful synergy has always been the most important aspect in personal audio. The X1s GT has the ability to insert itself in many different setups thanks to filters that actually matter. Some are slightly brighter, darker, etc. As far as playing well with sensitive gear I was pleasantly surprised with the lack of hiss when using the X1s GT with BA IEMs..

As far as weaknesses go, I can only identify one. The single ended output is indeed weaker than the balanced jack. While it had plenty of juice to power my 650’s if you were to use something like the HE-6se going balanced would be required. I did try this combo and was pleasantly surprised to hear them being driven convincingly. The X1s GT put up an impressive performance.

Have a friend getting into the hobby who is asking for some recommendations? The X1s GT should be at the top of your shortlist. This unit is absolutely perfect for my son who is into PC gaming and is getting into music. Having it in has allowed me to both enjoy it's sound and share the hobby with him in a unit that isn’t overly complicated, bulky or intimidating. I love that I can route a pair of RCAs from the fixed output to another amp so we can listen to music together without fiddling cables. It’s proven itself reliable and drives every headphone we’ve tested it on with authority. It performed well with music, movies and games.

There is no doubt I could live with this unit as my main kit – It’s dethroned my DS Schiit stack in a pleasantly surprising way and sent it right to the FS forums. In a way it makes me reconsider what I ACTUALLY need on my desk when I've given so much real estate up in the past to sizable separates. Needless to say I give the Aune X1s GT a strong recommendation, absolute even when you start to consider the price bracket and form factor. It’s easy on the ears yet engaging and capable. Aune has delivered on the X1s GT - a really exciting showing at that.


At our local Denver Head-Fi meet impressions for the X1s GT were quite positive. The sense of a surprising performance from a small unit was evident. Mentioned strengths were the X1s GT's well extended frequency range and engagement factor. Given all the gear available at the meet I was happy to see the X1s GT stand on it's own. For 99% of listeners, it's all you'll ever need.
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Headphoneus Supremus
Questyle CMA Fifteen, a worthy successor
Pros: Sound quality, features, powered pot w/remote, input selection, output connectivity and build quality
Cons: Quality demands a greater price
CMA Fifteen Review:
Today I bring you a glimpse into experiencing the new Questyle CMA Fifteen current mode amplifier and ES9038Pro DAC/Pre. While this new unit from Questyle at glance is strikingly similar to the previous flagship model, the Twelve, similarities stop there. There are some stark differences under the immaculately crafted hood that we’re going to be going over today.

Before we start however let’s get some disclaimers and information out of the way. Questyle as a company has undergone some major changes at a management/customer service level recently. I’ve been fairly critical of this in the past however I've had a recent experience with them that has instilled major confidence in where the company is headed going forward. I’m excited to see this change as a Questyle customer. I’ve never had a unit fail (I’ve sold my old 400i&600i to friends and they are still going strong to this day) but if by chance an issue came about I know I’d be well taken care of. I’ve ordered parts however prior to this review and the service displayed was expedited to a level that was blistering by any company standard. So, kudos to Questyle for stepping up.

Secondly, I am not being paid for this review. I have no incentive to pull any punches and even went as far to take this review unit to the local Denver head-fi members meet for others to experience and share their impressions, so let’s dive right in.

Fit and Finish:
One word says it all here, and that is Foxconn. Quite possibly the highest quality company when it comes to manufacturing electronic components in the world. The CMA Fifteen, like the twelve before it is manufactured in the same facility that churns out iphones and ipads. Every piece on the Fifteen is milled and fits together perfectly. This is hands down the highest build quality of any audio product on the market – and by a significant amount.
Heat transfer is significant and sinking is done properly within. I honestly can’t find a single fau.. oh.. oh wait, what is this on the front? Personal distaste for MQA aside the logo branding above the headphone output sockets would be better placed on the bottom of the unit. Sort of makes me liken the Fifteen to a Mercedes SLR with some Turbonetiks stickers slapped on the front windshield. On the plus side these logos are simply screened on and quite easy to remove. There are gain switches as well, inconveniently placed on the bottom. They are however significantly easier to toggle than the twelve. These are positioned at this location as to have the least impact on sound quality I’m assuming. I never felt the need to fiddle with them unless using ultra-sensitive IEMs, which I don’t use on desktop gear anyways.
Power switch is on the front and convenient. Strange this still has to be mentioned in 2022. IR receiver is nearby for use with the included remote which controls input switching and the motorized alps potentiometer. Very nice. Simple flip switches on the front also enable DAC/Pre or AMP modes with a bonus Bias control toggle just as the Twelve before it has.


Gone is the useless proprietary wireless module in the Twelve! This is replaced by my preferred BT protocol LDAC and it works flawlessly. I didn’t experience any disconnects or stutters from my Oneplus 7T during testing. They even added a simple pairing button for ease of use. Other inputs include USB C, USB A, Optical and Coax SPDIF. I’d consider this extensive considering the size of the Twelve. Next to the digital input section is the inclusion of RCA analog input which is akin to the previous generation 600i. I’ve heard many complaints about this not being included on the Twelve and Questyle has obviously listened. BAL amp input would be great but again, given the size of the unit this would not be possible. The input that is there works flawlessly though, but given the performance of the DAC section you may not need it. Still, great to have for comparisons.

The most interesting output for me is the Stereo/Pre section which consists of the usual RCA and XLR variety that output simultaneously. Questyle has included toggles for both fixed and variable volume control modes on the back and even has a toggle for use with both consumer and pro grade power amplifiers. Having this selectable allows users to use true pro gear to its full potential. This puts the Fifteen into a rare category for features.

Headphone outputs are the usual fare albeit of very high quality. The XLR is recessed so that it is screw mounted into the front panel for rigidity and it’s something that I can feel. On many other amplifiers when I socket XLR cables I can feel some ‘wiggle’ in the connector. Not so on the Fifteen, this possible wear point has been eliminated. Other outputs are 4.4 BAL and 6.35mm SE. I was pleasantly surprised that the Fifteen’s SE performance was above the Twelve – not sure what they’ve done to achieve this but it is welcomed.


Sound Quality:
Here we are, time to talk about PRAT, Dynamics and character! Just kidding, I won’t go into too many flowery terms without contrast and reason, albeit subjective in nature. I’ve heard many headphones, DACs & amps in my audio review and ownership journey. One thing that has become more frequent as of late however is gear that eventually induces fatigue. The quest for aggressive dynamic swings seems to never end. When I listen to my Twelve I am instantly captivated by the detail, power and engagement it offers. This eventually subsides however when fatigue eventually sets in. Depending on what I'm listening to, it could be sooner than later.

We’ve all experienced this to some extent, really you can only listen to headphones for so long before things get grading eventually... or so I thought until trying the Fifteen. Dynamics are present but they aren’t harsh and don’t make me wince at times like the Twelve does. I thought this would result in the Fifteen being ‘softer’ however vocal shifts on my favorite tracks still retain bite and warmth. String plucks and drum slams sound more ‘grand’ and come across with awe as opposed to being aggressively present.

Compared to the Twelve I heard significant sound signature differences between these two units. The Twelve has more aggression in the upper mids while the Fifteen had a more genuinely prominent and detailed midrange, tighter bass and smoother highs. Speaking of, Bass is fantastic on the Fifteen. It retains the current mode flesh while skipping the exaggerated boost the Twelve had in the lower mid and sub region. This notation continued on as I compared the Fifteen to other stacks/gear. Mids are more fleshed out, detailed and engaging on the Fifteen thanks to the new Sabre chip. Highs are more convincing and again, grand when compared to the Twelve and my other DACs. It’s there to enjoy and it's presented in a way that can be enjoyed as long as you'd like.

As a comparison Gustard’s X16 is what I consider the most non-offensive DAC ever made and is the one that I could previously listen to for the longest without fatigue. It’s also fairly flat and relatively dull in respect to transient performance… I don’t know how or why, but I can listen to the Fifteen indefinitely with all of my headphones and it remains engaging and again, I can’t overstate this – retains this ‘grand’ sound to its presentation. Soundstage is wide and deep, without any holes and instruments are articulated well while still carrying warmth and precision - a rare feat. This is a flagship showing for any DAC/Amp by itself and is an astonishing performance for an all in one.

Cutting the fat aside, this is the best DAC/Amp combo I’ve ever heard and the shocking cherry on top is that it is also the only one I can comfortably listen to long term indefinitely. Questyle says they engineered this unit for over three years – and it has paid off. It'll be hard to top this unit going forward as you’ve already struck solid gold with the Fifteen. Oh, and on a side note the Fifteen also has enough power to push the HE6 without issues. It’s quiet with sensitive IEMs in low gain mode as well. I tried 9 headphones with the Fifteen ranging in design and power requirements. I never ran into any situation where I felt the need for more power.

Pre performance was exemplary with both pro and consumer gear. My crown amp put out more power than I've ever heard thanks to the voltage toggle on the back. With my Akitika the soundstage was massive and and my system was incredibly engaging. I'm using LS50's that are very sharp with certain DS dac pairings, I'm happy to report the Fifteen had no such issue and pushed my LS50's better than I've heard before.

Pricing & Conclusion:
Aaah the pain… Quality and performance always comes with a price… for the Fifteen it’s over 2 thousand. Is it worth it? For the functionality, performance and quality the Fifteen possesses I’d give it a resounding absolutely. Keep in mind this would replace your: Dac, Amp, Pre & Pro compatibility gear. All in a single easy to keep on the desk aluminum chassis with remote & powered pot.
On top of that I’ve never heard a unit present sound like the Fifteen has. If my budget allowed I’d already have bought one before sending this review sample back. Heck, I may just have to ship them back a brick and fall off the planet because with the Fifteen my personal audio journey would be a wrap. Having this in my collection would relegate a LOT of gear and prove to be an almost impossible uphill battle for future review pieces to climb. I don’t think I’ve ever given such a glowing review and recommendation on a piece of gear, and as a reviewer it's exciting to see pieces like this release. Just don’t forget to scrape the stickers off this Mercedes.


Several participants were able to compare the Twelve to the Fifteen at the Denver Head-Fi members meet. I’ll be summarizing their notes comparing the two and adding my personal thoughts on them. Remember, these are meet conditions so shorter listening sessions. Both units powered through all headphones tested on them, which included some demanding ones. Attendees noted clear differences between the two.

Thoughts on the Twelve: More perceived dynamics and frequency range, big bass, can be fatiguing but is also very engaging.
- Personally I agree with all of these impressions
Thoughts on the Fifteen: Cleaner sounding, slight compression, much higher quality bass, more forward midrange, very engaging.
- I agree with quite a bit here, less the compression part. In comparison to the Twelve’s much boosted subbass range the Fifteen may seem more polite and make one automatically think compression – however the bass is very present and incredibly detailed. It’s only when I spent more time with the Fifteen that I was able to really pick this comparison apart. The Fifteen’s bass is much like other kits of gear that I have except again, more fleshed out and engaging. It’s only when compared directly to the Twelve that it’s quite boosted bass gave me this same impression.

You’ve stuck around this long.. I want to thank you for the read and wish you the best in your audio journey. A huge thanks to Questyle for not only the big changes they’ve made to their company recently but also for hosting this Head-Fi loaner tour. A big thanks also to you, members of the community for keeping this hobby alive and thriving during difficult times.
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I was a participant in the CMA Twelve tour, and commented to the Questyle representative in a PM I wish I had a CMA Twelve during this tour for a direct comparison. Lucky you.
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Both are really great units, but the Fifteen is definitely a step up - as it should be for the price.


Headphoneus Supremus
xDSD Gryphon Review
Pros: Sonic performance & staging, excellent tonality, aesthetically pleasing, BT performance, musicality
Cons: Cybersync (Volume Sync with device), noise floor with ultra-sensitive iems & IEmatch increases output impedance, battery saver doesn't work and no setting to enable it. Sub bass rolloff/freq compression.
Earlier in the Gryphon thread I had posted some early impressions and comparisons of the xDSD Gryphon compared to some other units. While those impressions still stand after a good number of weeks I've become more familiar with the device and would be happy to share my full review. The xDSD Gryphon to me strikes a fantastic balance between neutrality and musicality. The device is linear with a wide sound stage yet doesn't let the analytical nature of modern devices take over. Going forward let's cover my thoughts on the features and sound quality of the device.

As a disclaimer my xDSD Gryphon was purchased personally and was not part of a demo/review program.


The xDSD reminds me of the iDSD BL series in terms of system compatibility - even more so with what they've crammed into this device. 4.4mm is the new standard for mobile friendly balanced (and for good reason) and is the perfect choice for the Gryphon. With it you get the full power for your harder to drive headphones. On the back you've got 3.5&4.4 connections that can either be used as output from the internal DAC or inputs to use the Gryphon as a dedicated headphone amp. XBass&XSpace are rather enjoyable implementations that do not overpower the sound like some previous devices did when enabled. With my stable I did not prefer using these but I can definitely see it's use for certain headphones or perhaps listener preferences.

Easy swapping between USB, SPDIF, BT and Line In are possible with the front buttons, as is accessing the menu and navigating it. It's incredibly easy to get the Gryphon running and the speed of swapping between each of these is blisteringly fast. It's so nice being able to get the Gryphon going in just about any scenario I want with excellent results. Bluetooth performance is exceptional as well with only a minor degradation in sound quality, you'll really have to focus to detect the difference between wired and wireless.

The Volume knob changes colors based on power output easily letting you know where you're at and the tactile feel of it is incredibly pleasing. The buttons are easy to use and the screen brightness can be adjusted. Fit and finish is exemplary and it shows that Ifi took their time on the hardware side of designing the Gryphon. Jacks are all solid and there is little concern for durability with the Gryphon. The screen is bright and clear, and doesn't appear to induce noise which is fantastic. I do wish they'd used glass instead of acrylic as a cover for the screen but, this is a minor nitpick.

**EDIT** The Gryphon has a built in battery saver, this is always enabled. Great job Ifi!
Missing however is an ability for eco battery when used as a desktop DAC/Amp. Ifi states to turn on the device then plug it in so that the unit doesn't charge all the way, though in practice I've not had much luck and you'd have to unplug and turn it off every time you are finished using it, then turn on and plug in when you are ready to go again. There is an option in settings however to have one cable both charge and supply data - which is an excellent toggle addition if you've got clean USB. If the battery charge control would be implemented as a menu option in settings the Gryphon would be a completely desktop friendly device in my opinion.

Cybersync is a feature better in marketing and not so much in practice. This allows the volume of the Gryphon to be controlled by the device it's connected to. Ever accidentally maxed out your OS or phone volume with too long of a button press? Imagine that combined with 1W of power and a set of IEMs. Before a firmware update was provided by Ifi myself and others had experienced volume spikes between tracks in certain players and in other scenarios with the Gryphon. When dealing with 1W of power and a device marketed as IEM friendly this is a big problem.

Firmware has thankfully corrected most of these volume issues, but knowing I could accidentally adjust the volume on my android device while it is in my pocket is a constant worry. What if my phones volume button were to be held down while exercising or moving about blowing my ears out or damaging my IEMs? This concern has made the Gryphon unusable while on-the go and forced it to the desk or sitting positions where I know I've got full control of the environment. A firmware option to remove this 'feature' would be very welcomed.

IEmatch is another feature issue of the Gryphon, though mostly for users of ultra-sensitive IEMs. Unfortunately as a CA Solaris owner I was impacted here. The Gryphon is very powerful, and thus the noise floor presents itself with ultra-sensitive IEMs. The 4.4mm IEmatch setting squashed dynamics and changed the FR of my CA Solaris IEM. Without IEmatch the Gryphon hissed quite loud. 3.5mm is serviceable, though not ideal. The output impedance changes up to almost 10Ohm with IEmatch enabled which is important to keep in mind. With other IEMs I did not have an issue and the Gryphon performed incredibly well.



The Gryphon's signature is more neutral leaning with a hint of warmth. It's decently fast yet not sibilant. I think it's a rather nice balance however I will start with the obvious "Birth of a Head-Fi legend" as being a bit of a marketing overstatement. It's not nearly as fast and detailed as my dedicated desktop devices, though it is important to note the price of the Gryphon is a fraction of what my desktop rig costs.

What does push it towards legendary though is that I prefer it's presentation, sound quality and overall experience to the iDSD BL. For a do-it-all device this puts the Gryphon into being a benchmark for this segment. The soundstage is well represented with fantastic positioning. Instruments are defined and the three blob soundstage of the iDSD BL series is gone. This is replaced by correct placement and significantly more precise imaging. A very slight bit of warmth really helps the package come together. Mids are fluid and come across neutral yet are forgiving. Highs are extended and airy with great sparkle. Bass is engaging and tactile, despite not being the end all in bass resolution I've not heard a device this size present such a fantastic grip on the lower registers. It however does not dig deep into the sub area, pushing focus towards lower mid bass. This is still an incredible accomplishment for Ifi.

As a DAC the Gryphon performs admirably well. Feeding a signal into my Freya S was made easy with a 4.4 to XLR L/R cable. The experience was more than acceptable and I was toe-tapping in no time. The Gryphon is so incredibly close to a do-it-all device leader in it's price segment. As an amp I felt the Gryphon did quite well. I feel that the amp of the Gryphon has it's own sound characteristic - and it's a rather pleasing sound at that. Given the internal DAC performance though I don't see myself using the Gryphon as a dedicated amp. The Gryphon shines as a combo plenty bright.



The Gryphon on a hardware level is a fantastic device. Nothing on the market currently is pushing such a diverse featureset like Ifi and the Gryphon's sonic performance carries it to the skies. Unfortunately software and marketing choices have kept Gryphon from being above the clouds. Ifi can easily correct these issues through updates, aside from the IEMatch/Noise floor - this is a hardware level problem impacting Campfire IEM owners but let's be honest, MOST devices have problems with CA IEMs so this really is a nitpick of compatibility. If Ifi was to offer a Cybersync free firmware and proper battery saving this review would easily be rated higher and I'd be free to use this device on the go, in the chair and at my desk without any issues or concern. If this occurs I shall update my review - thanks for reading!
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It does not. 3.5 is serviceable, 4.4 is completely crushed. This is with 4.4 output - 3.5 setting still impacts 4.4.. it's... weird. I'll need to test 3.5mm output on its own. It is likely much quieter.
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Hey @Voxata, can you do a quick comparison with your WM1A pictured?
It was in my prior comparison. I prefer the soft modded WM1A for it's unique flavor.


Headphoneus Supremus
Pros: Build quality, detailed, easy to drive
Cons: Light bass, forward treble, short and stiff cable
Focal Elegia Review:

I want to start off giving thanks to Todd of TTVJ for putting these up for tour. He has offered all types of different equipment for us to experience and this definitely doesn’t go unnoticed in the community. My first experience with Todd was when on a tour for a quite pricey Audioquest power conditioner. I tried for the life of me but couldn’t rationally put a review on something in which I couldn’t tell a difference in my chain. Still, thanks to Todd I learned that in my situation I wouldn’t benefit from such a product and I am thankful for that.

This time around I’m very excited to actually have something in my hands to put words to. I’ve always wanted some extended time with a Focal product and that day has finally come. When I’ve visited CanJam given the show conditions, different setups and other factors I’ve never been able to really take things in at my own pace. These tour allow me the time to really take things in and make an educated purchase decision and develop my tastes further in audio.

I’ve been keeping an eye on the market for a closed back headphone and with Elegia in my budget and on my radar this tour has come at the perfect time. I’ve plenty of experience with closed back headphones ranging from my beat’em up DT770, Ether C 1.1 and Shure 1540’s. I’ll touch on a few key areas on the Elegia.

Comfort – The cups on these headphones fit with room to adjust to preference. Sound is not impacted heavily due to positioning thanks to the angled driver. Clamping force is present however given the metal yokes can be firmly adjusted if need be (I did not do this, it is a tour pair after all!) The headband is solid with perforated leather at the top of the head however pleather wraps the top of the headband which I’m not a fan of. Weight is however evenly distributed and I did not have any pressure spot issues. Isolation is not the best given the light velour pads with perforated inner section, however it wasn’t anywhere near as bad as the Shure 1540’s.

Durability - The Elegia cups are primarily plastic which is alright as it saves on weight. They have heft and feel great in hand. The only issue I’ve got here is with the pleather over the top of the headband. If this was to get worn it would get unsightly very quick.

Sound – For a closed back these sound quite decent. Easily besting the DT770’s of course and playing with the bigger contenders. However, for *my* preferences the treble comes in a little forward and the bass a bit shy in the lower mids. This was most noticeable on guitar plucks and drum hits however some genres this actually played quite nicely with. Vocals are portrayed with clarity and are engaging. Violins are crisp and the treble has great sparkle and expanse for a closed back headphone. These generally played nicer at lower volumes, anything much higher would bring forth fatigue.

Scalability – With gear changes the character follows suit however this is minor and these are very easily driven from just about anything. They saw little benefit moving up my ladder of gear which isn’t necessarily a bad thing as you won’t need $1,000 worth of equipment for the Elegia to sound great.

In closing you may think I’m pretty mixed on my impressions on the Elegia. Actually I’ve truly enjoyed my time with it and I’m quite curious what else Focal has to offer. Sadly, for my preferences this headphone is not what I’ve been looking for as I prefer a bit more laid back treble and neutral or very slightly lifted bass. I did however find quite a few songs that clicked well with the Elegia and when this headphone clicks it does so quite well. Some people stick to certain genres however my tasted vary wildly so strong all around performance is a must in my book. I'd give it a 3.75/5

Gear: For this review I used the following

iFi iDSD Silver

Grace SDAC+JDS Atom

Topping DX7S+THX789

Fiio X5iii
Given your sonic preferences, which closed back cans did you move on to?


Headphoneus Supremus
Pros: Clean, powerful and BEAUTIFUL
Cons: Runs warm, battery life, midcentric focus

It's that time folks! I've got a new offering from Aune in the form of a powerful portable amplifier resting in my hands. Before I start with the juicy details I'll start with a little info about myself.

I listen to a wide variety of music however my test tracks vary from EDM, classic rock, classical, alternative and everything in between.. alright alright.. no country :) I'm an over ear kind of guy as IEMs don't get me where I need to go when it comes to musical enjoyment. On a side note, I'm not being compensated in any way for this review. My thoughts are just that. Also I've come to appreciate the sound each piece of equipment has to offer and realize the importance of synergy. Some chains just simply don't sound right.. finding the magic isn't always easy my friends.


Enough of that.. I'm sure you want to hear about the B1S already right?! Well, I was a bit hesitant when I read up on the original B1's main complaint of not having enough driving power. I can honestly say however this can drive the toughest of my cans into a flaming pile if I got dial happy with gain and the class A switch enabled. The only can I would say wasn't driven 'well' was my HE-560 which seems to really, really like gobs of power to get where it needs to go. It got loud, just not full. How many people are going to be specifically pairing that kind of headphone with the B1S? Yeah, none.. but it is good to know :) Excellent pairings were with all of my dynamic headphones and even the LCD2C did quite well.


Some like to say every solid state amp sounds the same.. well - I have to disagree. Every amp I've heard has a variation.. its own sound signature. It doesn't swing as wildly as some say but it is definitely there. The B1S's signature I would say is a very friendly tuning. I can listen to the nastiest of my demo tracks (they are there specifically for a good reason) with ease on this amp. There is some deep sub bass roll which honestly I appreciate. Some very low frequencies can cause a bit of discomfort in some of my amps in the tune of fatigue.. not so with the B1S. This can also be said about the extreme highs, which have sparkle but don't seer my ear hairs right off.

The B1S CAN be a bit of a midcentric amp depending on the setup, however this also gives it the ability to pair so extremely well with many types of different headphones and sources. I can't stress enough, this is a subtle thing, and something that makes this amplifier able to please more of an audience. For something portable and easy to tote you definitely want a tuning like this. Aside from that the B1S is a surprisingly neutral amplifier. Very clean, very powerful and quite worthy of mating with any DAP.

The bass hits with authority and is visceral through the frequency range with smooth transition despite a low amount of roll at the bottom. The mids are heaven for vocal music and retain great warmth. The highs are extended yet controlled at end of the spectrum as to not pierce, even if the source material does. The tuning has only one downside, it is easily appreciated but not immediately engaging. It all comes down to your tastes however and I must say this amplifier is worth trying out to see if its your cup of tea.

Dimensional aspects of the amplifier are decent, although a little bit bulkier than my X5iii.

IMG_20180210_164027.jpg IMG_20180210_164019.jpg

Sure does look absolutely beautiful though. It does come in a black color as well so.. definitely one of the most eye appealing amps I've ever seen, with good sound quality to boot. There are a couple of downsides to be aware of. It did get a bit warm in Class A mode after extended use and when enabled the battery life wasn't the greatest. A bit of a SQ hit when disabling this feature but nothing to write home about.. honestly, I'm not all sold on this feature as it is just another circuit being introduced into the mix.

When compared to my Fiio A5 the sound was cleaner.. more neutral however less engaging as the Fiio reached deeper. The A5 is more colored in the way it alters the sound though. It all comes down to flavor and what cup of tea you prefer. When using my iDSD BL as a source I did prefer the BL's integrated amp - however I'd say this comes down to synergy. Take comparisons with a grain of salt, my ears are very different than yours:) I can honestly say though that this amp is definitely worth the asking price. Some pieces of review kit don't get listened to every day for the duration... this one did :) It'll be missed. - Thanks for the read my fellow fi'ers!


Sources: BifrostMB Gen5, iFi iDSD BL, Fiio X5iii, Galaxy S Voodoo Ed.
Amps: iFi iDSD BL, Jotunheim, Fiio A5
Headphones: Sennheiser HD6XX(Modded), Hifiman HE560 and HE400i, AKG K702(Modded), Audeze LCD2C, Beyer DT770(Modded)
Makiah S
Makiah S
Love the K702s as well! Thank you for your thoughts


Headphoneus Supremus
Pros: Metal body, 4490 DAC with a sturdy volume knob based on Android
Cons: Plastic screen, still needs an external amp for 250+ Ohm headphones.
    Today is my long overdue review of the Cayin i5. I had trouble getting this review complete due to a holiday emergency and a slow recovery however, better late than never. 
*disclaimer* I've received this unit on a tour for a week in exchange for my honest opinion. I am not affiliated with Cayin nor am I being compensated in any way so the following will be unbiased, honest and true to my experience with the i5.
    Looking at the build quality both impresses and also leaves things to be desired. Here we've got a great metal feel with a solid weight in hand. Excellent looking carbon fiber on the back and the volume knob is firm and robust. There is an elephant in the visual room though and that is the decision to use a plastic based screen that will become completely marred after little use. I received the unit scratched thoroughly.. There are a couple of screen protectors in the box so if you get an i5 apply one immediately. Including them however is a nice touch. Nevertheless, for a product at this price level I'd be wanting glass.
    When it comes to sound quality I must say that mobile units still are not up to taking on the desk, however, they keep getting closer that is for sure. That said, my headphone inventory is fairly hungry. I've tested the 650, HE-400i and DT770 with this DAP. I wouldn't recommend the 6XX series of headphones without a serious amp addition. The 400i was borderline, however sounded good considering. The DT770 sounded great. There is a lot more to amp needs than volume. Sure, the 650 got loud however it was also flat and lacked dynamics/punch with clipping. As such my testing was primarily with the 770 and 400i. 
    Listening sessions were impressive for a mobile unit. Sure, I'm spoiled at the desk using BAL and HE-560's but.. one has to have a decent portable rig to enjoy too right? The i5 fits right in there with its small size, enjoyable listen and with its android powered core it is quite the flexible and capable player. I have mixed feelings at times with the 4490's bloom however on my headphones it wasn't detracting. The sound stage was just right. Details were there with a bit of a warm touch to keep things smooth, which I believe is important on a mobile unit. The DAC section is done right.
    There was a bit to be desired when it came to dynamics and experiencing sound coming out of nowhere with depth and authority. I'd mostly attribute this to the need of a stronger amp. If you've got more efficient headphones I doubt this will be an issue for you but.. for me, I added the Jotunheim into the mix just to test my theory. Once I did this, I was pretty impressed. This wasn't a notch below my old 4490 DAC which was excellent as I'd really have to hunt hard track down the differences. The sound stage lifted and authority came through in troves as well. Again, this is only an issue if you are like me and have an inventory of power hungry headphones.
    If I were to add one of Cayin's portable amps to this equation I'm fairly certain I would be very satisfied with my full range of headphones, as exhibited by using the i5 as purely a DAC. Overall, I enjoy the player.. If it had a more quality screen cover and a bit more oomph, it'd be a quick buy in my book. However, if you own more efficient pairs of headphones, IEMs or the like the i5 is quite the compelling buy. The SQ is smooth and fantastic, with an engaging enjoyable listen which really is the point of a mobile player in my opinion. Many mobile players go down the detail hunting track which really kills a few less than well mastered songs. Leaving you skipping tracks to find something enjoyable. The i5 sits in the middle, still giving you detail but not throwing it into your face.. This is a very good decision on their part.
     I've not looked towards Cayin for possible purchases yet, however with this unit and given they are quite receptive to feedback I'll be keeping an eye open in their direction for sure. Also worth noting battery life was solid and depends on how much time you use the screen, as it is a sizable one. Firmware was a bit groggy (it was also very expansive), however since the unit had not been out long I'm fairly certain they've ironed those issues out nicely. 


Headphoneus Supremus
Pros: Small size, incredible detail, pre-amp out, remote, bang for the buck, build quality
Cons: Only USB input
 I've been given a chance to review the soon to be released Burson Conductor Air, which I'm quite thrilled to do given the form factor and specs of this unit. I'll be comparing it to a few other DAC/Amp combos I own and have heard extensively. This includes a Burson V5 OpAmp equipped Asus Essence STX, the legendary Galaxy S Voodoo Mod + FiiO E11 Combo and
Schiit's Bifrost 4490+Asgard 2. The headphones I'll be using will be the Hifiman HE-400i, Beyerdynamics DT770, and Ultrasone Pro 900's.
       I like keep my thoughts fairly brief and highlight the key strengths and weaknesses I believe are characteristic of each configuration. I will focus highly on the Air however given that it is the heart of my review. As a reference I spend a couple hours on each song swapping gear, volume matched as best I can noting down my impressions. Be aware that the differences between these setups are very apparent to me.

      For reference the music I'm listening to includes: Radiohead - Sail to the Moon, Skrillex - Kill Everybody, Metallica's S&M - No Leaf Clover, Led Zeppelin - Moby Dick, Atmosphere - Southsiders, Perfect Circle - By and Down and Korn - Make Believe
    Asus Essence STX/V5 - Really great depth here, the V5 upgrade lowers the noise floor of the STX considerably and adds a LOT of weight and realism. This soundcard would not be a contender without it. This plays well with all of my headphones, however instrument separation isn't the best and some of those sounds and symbols that come in on the sides of the soundstage are not as clear as they could be. I do not have the cap mod however, which I've been told will clear some of this up. Regardless, I've got a smile on my face from this setup with each set of headphones.
    Burson Conductor Air - Excellent air, pun intended I suppose..  Coming off of both the V5 and Schiit setups this was one of the first things I noticed. Instrument separation is good with sounds coming from where they need to be and the power is definitely there. Vocals have great depth and presence with a strong center stage, which is really quite involving.
     I did however feel at first that the sound could be a tad more weighted on the HE-400i's in my testing. This symptom disappeared upon the unit 'warming up'. After a short while the Air runs warm to the touch, however I would definitely not consider it hot.
     Now for the big news.. I can also honestly say you can rest assured all of the micro details are there and then some. Specifically on Led Zeppelin's Moby Dick the Burson Air was able to pull considerably more detail and harmonic resonance during the intro than even the 4490+A2 combo. Also an important take-away is that the Air performed better with my dynamic cans than the Schiit/A2 setup even over SPDIF, besting the stack on both the DT770 and Pro 900 headphones especially in the detail department. The HE-400i shows the strengths and weakness of each setup, so I'm going to call that set of cans a tie to be broken by musical preference/mood.
    Galaxy S Voodoo Mod + FiiO E11 Combo - This combo combined with the Pro 900's is synergy heaven. The Pro 900's specifically performed better on this setup harmonically than any other. However this setup could not complete on a detail level with the Air or 4490/A2. The STX retrieved the details slightly better than the Voodoo+Fiio, however, they were also slightly blurred due to my card not being cap modded. The HE-400i's were not enjoyable on this setup at all. The DT770's were decent though. The Pro 900 synergy is where the magic is here, however the Air+DT770 sounded better.
    Schiit Bifrost 4490/Asgard 2 - Not much to say here, a fantastic experience that many ears have shared. I've found that dynamic cans sound pretty thin on it though. The Pro 900's do not work well on this setup. DT770's do great, however that thin nature remains. The HE-400i's however are quite at home and have more depth and fullness to the sound than any other setup, albeit at a loss of detail.

    There is more on the table than just the sound with the Burson Air though, and that needs to be addressed. Don't get me wrong the Conductor Air sounds great however this unit serves more than one purpose. I like that it has
the jack-of-all trades thing going for it while mostly avoiding the master of none pitfall. This is what makes the Air as appealing as it is.
    First let’s talk about portability, this unit does not have an internal battery - which given the power output I don't exactly believe it would last too long even if it did given the size. You won't be tossing this in your pocket with a DAP and battery bank then going for a jog, and this unit isn't designed for it either. However I've tested it with my bank and it works great as a travel/backpack or work setup.
     The casing is very rugged, as is the remote casing which is a big plus. As a comparison my E11 with its cheap casing is starting to look like a pop can that has been crushed and reformed. The Air may lightly scratch over time, but it won't dent. The casing on the remote is set to match, and both units feature a nice magnetic system making the product seamless without screws.
      I do see many people wanting to compare the Air to the Mojo, and I'd say they have different purposes.. If you're 100% mobile, I'd be inclined to recommend Mojo due to the internal battery. However, if you plan to use this as a dual purpose portable or leave it plugged to your PC as a preamp or on all the time I'd be suggesting the Air. I've enjoyed a friend’s Mojo for a week and it gets incredibly HOT. It’s got a lithium ion battery, there is no safe way to run a battery that hot all the time or unattended. I don't care what a manufacturer tries to claim it just isn't happening for me.
       The Mojo is great in its own right, however in my eyes it is a purely mobile unit. I won't comment on sound quality between the two as I did not A/B them, however I can say I've never heard the amount of detail from Zepp's Moby Dick that I have heard when listening to the Air this week.

    Now we're on to multi-use, this unit has a LOT going for it. It sounds better than the STX V5 on my home theatre setup thanks in part to the detail retrieval and it has a remote for ease of use. It can also be set upright on my case so that I can see the volume clearly, especially in low light. With the Air users can also retire their soundcard and go ITX form factor... can't tell I've been wanting to do this for a while can you? I was also able to easily pull it and use the Air for bedside duty with my Nexus 5X using an OTG adapter. On another front I do play competitive CSGO on my gaming PC and I'm happy to report that the positioning was stellar. Another bonus is not requiring an additional power connection, so it is LAN/travel ready. Check check check and check. Side note, the unit itself has volume up, down and a mute button as does the remote. Preamp and headphone out, a USB power connector is needed when in use with OTG. Connecting via a PC USB only requires the one connection.
   Downsides? Well, there is one downside to this unit. I prefer the SPDIF input option on any external PC usable device. While many have different views on this topic I believe it did not detract from the positive experience. It isn't a buzz kill for my purposes, but the future inclusion would be nice. All in all, I definitely give this unit a thumbs up especially at the early bird price point it's a steal. The sound is there, the versatility is right there with it. Burson has been on a roll lately with their products, and I'm happy to report this continues with the Conductor Air. I hope you've enjoyed the read and a big thank you to Burson for giving me a chance to try and review the Conductor Air for all of those interested.


Headphoneus Supremus
Pros: Authority, presentation and musicality
Cons: Size
 So I've gone ahead and upgraded my STX using the Burson V5 Dual Opamps (x3), I've seen quite a few in this thread ask if upgrading opamps in general is really worth it so here are my impressions, YMMV of course.
     Before I start it should be known that I've owned my Essence STX since 2009.. yeah, I had to look up how long. I only know this because I purchased it at the same time Windows 7 was released. This card has lasted through MANY computers and headphones, I don't think it'll ever stop working. It has sat above hot running GPUs (fermi) and been in poor airflow situations. I've rolled about half a dozen opamps before settling on signatures I liked. I have two different sets of opamps I prefer. One set which sounds best for headphone use, and another that is great for my speaker setup when using the card as a DAC. In short, I'm very familiar with what the STX brings to the table. 
     My headphones are currently Hifiman's HE-400i and DT770 Pro 250's from Beyer. My speaker setup consists of a Carver M200t amp, and Event 20/20 speakers. I also have a Bifrost/Asgard2 stack that I use for music listening which I purchased six months ago.
    The following songs well known to me, I'll be sharing general impressions on my various setups. 
     First though, I'd like to note that the packaging for these opamps is top notch. They include risers (which I did not use, to help ease fitting in my case) and have quite the quality feel with solid non flexing gold pins. If you've rolled opamps before, you know how nice it is to have a quality rounded pin setup because those cheap ones bend like no tomorrow. 


Songs: Led Zeppelin - Moby Dick, Atmosphere - Camera Thief, Metallica S&M - The Call of Ktulu
STX : Coming off of listening to the Schiit stack for a while these tracks sounded flat on the STX w/my 'upgraded opamps'. A black background with strong presence, clear soundstage and natural presentation is extremely important especially during the large drum solo, and this setup didn't have it. Breaking the Moby Dick track out early quickly showed me how much of a gap is between the STX and the Schiit Stack. Piano keys are not convincing, the worst culprit being the 400i's with obvious tonality issues on the upper end. 
STX w/Burson V5's : Woah,,. wait a minute. I'm pretty sure I must mixed something up between my bench and computer desk. This doesn't sound like the same card I've owned for ages. Musicality has greatly improved, tones (especially bass/mid bass) are now presented clearly and with authority. I have been known to boost the lows on my STX since they've always lacked the impact and body. This is no longer the case. The thin and brittle sound is gone and in its place a very solid linear presentation. The tonality of the highs are vastly improved on the 400i, they are now enveloping and simply engaging. Where the heck were these things 9 years ago? I'm really into these, after jamming out I'm thinking I really need to test this vs my $650 dollar stack.. 
Schiit Bifrost 4490/Asgard2 : This is the part where I settle back into being spoiled and don't look back right? Well.. Yes, presentation, staging and authority are improved however there is some seemingly obvious diminishing returns. Especially as both setups do seem to be limited to the quality of audio you're feeding it. Before the V5 upgrade this was not the case. Honestly, both setups are quite engaging now. I couldn't vouch for engagement before the V5 upgrade and I've spent some dead serious ear time on the STX.. Honestly, if I was in my return period for the schiit setup I would be returning it simply for the fact that it is many, many times the cost of the V5 opamp upgrade. 
        Will I sell the schiit setup? No.. it's definitely on solid bedside duty, however, my plans to upgrade my gaming PC from the STX are definitely scrapped. Looks like it'll keep going for quite a few more years. How awesome for Asus to make this soundcard upgradable, and major cheers to Burson for pulling this V5 opamp off. I've learned that the STXs amp section is the weak link, and this opamp has really overcome the problem. 
Carver m200T + Event 20/20 -- Bifrost 4490/Essence STX Burson V5 DAC : This is where things got real interesting, when comparing the DAC sections. The STX is well known to have a great DAC, and it also utilized the V5's in the link. When comparing these two DACs on this setup I was able to discern a difference between the two DACs, however, I was unable to decide on one that I hands down preferred over the other. I felt the STX was more engaging or musical, while the Bifrost was more detailed and clean. Each had its strength, this was not the case when I originally compared the 4490 to the STX with lower quality opamps.

       When you consider the cost gap between these two setups, the V5's have enabled the ol' STX to punch well above its weight class. This is a very worthwhile upgrade, especially if you're considering anything mid-fi to replace it.   Happy hunting all!
Great review. I'm extremely impressed with the V5 Opamps also and the main thing I learnt is that there is a huge gap between the standard Opamp rolling options and the Discrete V5's - it's almost impossible not to notice the difference immediately and rather than a difference that quickly becomes fatiguing (like some of the more 'wow' factor upgrades) the added transparency/definition comes with an inherent smoothness. Probably one of the best value upgrades out there despite the cost vs standard opamps.