Combine Quest, Style and a passion for high-end audio and that what the company Questyle were born from. Now they are a new company in the respect that their products are only just on the market but as a company they have been working together since 2005 and only now do they feel ready to release their creation onto the world, I mean this amp I am reviewing from them went through 22 iterations so they were in no rush and wanted to make sure their products were going to reach the demands of the market. Questyle have already seemed to really hit things off in a positive manner in China with their 5G Wireless HiFi system getting a great response at the Chinese national HiFi show. They also have two DACs, a cheaper headphone amplifier and an integrated headphone amplifier and DAC in the range but the product we are looking at is the CMA800R. This is a product with so many talking points about it, it’s a lot more than just another headphone amplifier in its price range and I am sure your going to be both intrigued and excited by the time your done reading this piece. The price of a one CMA800R is just over £900 from an authorized reseller on eBay, probably the safest and most hassle free way to go at the moment, although I think directly emailing the company will work.










Max Output Power


180mW (7.5Vrms) @300Ω, standard Stereo Mode



710mW (15Vrms) @300Ω, Mono Mode




114 dB, standard Stereo Mode



118 dB, Mono Mode




0.00038%@1kHz, 300Ω standard Stereo Mode



0.00026%@1kHz, 300Ω Mono Mode


Frequency Response


DC-200kHz (+0, -0.3 dB); DC-650kHz(+0, -3 dB)












 XLR stereo, RCA Stereo, and XLR Mono Full Balance input 




Dual 6.35mm Stereo headphone Jacks,


A XLR Mono Full Balance output, 


A pair RCA Pre-amp output 


Work Status


Pure Class A




100-120Vor 220-230V, Internal switchable


Power Consumption






330*300*55 mm



Lets talk a bit about the amp then. I may have mentioned it before but I am not too know it all when it comes to how and why amplifiers work, I try and understand as well as read up as much as possible but I am not going to try to make this a technical evaluation of the amplifier as such. Yes I do appreciate objective measurement and I do take them as seriously as you should but as a reviewer I tend to focus more on subjective opinions and experiences with an amp. Now this is why I just love how Questyle have gone about developing this amplifier. It seems the objective stuff come first, getting the technical specification and measurements to a very impressive level but they then started to get music engineers and artists to try it out to get subjective opinions on the sound and as a company have done their own blind testing with it alongside their measurements. Measurements are of course something the both pride themselves in and also test vigorously. Every single CMA800R they make is measured on 30 different specifications on an Audio Precision AP2722 (an £19,000 industry standard audio analyzer) before it is packaged and shipped along with your amps very own and unique measurement print outs. That is something that I find to be very nice, I mean, I guess it is necessary to be doing the thorough checks of the amplifier but getting them presonal measurements just feels very special knowing that they are not just the measurements they aim for but of your unit. It also works in respect to if you ever have to have repairs made on the amp, as they keep copies of the measurements with the serial numbers of your unit so that they can see what needs sorting out if anything was to ever go wrong, not something I have come in touch with as mine seems to work just as well every day. The following measurements are the ones they sent me for my CMA800R.









Now this is very low, I mean, you are not picking up a pinch of distortion with this amp and it also goes without having a single spike where a bit more distortion is present, something that normally does happen.






Batman would have trouble hearing the upper end of the frequency response of this amplifier, I mean the extension so far into the treble. It is also a perfect flat line from 0hz, which is always a good thing, as we do not want any nooks or peaks in the frequency response.



Now the amp is what they call a “Current Mode Amplifier”. It is their own-patented method and the idea is that the amplification takes place in the current stage in opposed to the voltage stage. Now this is something that is pretty much the norm in high speed communication and video processing but it is very unique in audio, with this being one of just two amps to use this technology as the Bakoon HPA-21 also uses it but I think does it in a slightly different way. So the benefits of this way of amplification, well instead of me putting what Questyle say into my own words, why not just quote them.



“In traditional Voltage Mode amplifier, the Common-emitter voltage amplifier is indispensable but its transistor impedance overloading is too much, so it causes the “Miller Effect” and greatly slacked its high frequency response. Besides, when the voltage mode amplifier is processing fast speed rising pulse wave and large amplitude HF output, limited by power and capacitor loading, it definitely causes Transient Intermodulation Distortion (TIMD). TIMD brings a “metal sound” mixed into music and causes obvious distortion, gives audience very unpleasant feeling. This is so-called “transistor sound”. But Current Mode amplifier, the capacitors is between each two transistors which affect speed and band width working in a low impedance resistance, RC value is ultra-low, so it can easily achieve amplification with much broad band and ultra-low distortion, avoid TIMD.”



Well taking a quick look of the measurements of this amp and that backs up the statement that it causes very low TIMD so it certainly achieves its goal there. As for it not having a lack of high frequency my ears say it allows the maximum extension any earphone/headphone is capable of while a frequency response graph shows the roll off to not pop up until clearly past 50kHz when in fully balanced and a bit less in single ended. Okay I have just mentioned balanced for the first time, your right, I have kept that quiet but I think it’s about time I talk about one of the most exciting features of this amp. In regards to more technical information, more about current mode amplification and other stuff like all the high-grade components this amp uses, I recommend going over to the Questyle’s website product page.



So originally there was a CMA800, which is now discontinued. Now the only difference you can tell by the eye is that the R (stands for reference) has the addition of a 3 pin XLR output next to the volume pot. However, there is just one 3 pin XLR output and that means it is not just the addition of a balanced output to the last version because, well, for those who don’t already use a balanced amplifier, you either can use a 4 pin XLR output or two 3 pin XLR outputs. One 3 pin XLR output is just no use at all, but don’t worry, it certainly justifies itself. Questyle have been a bit brave and decided they wanted you to be able to monoblock the CMA800R so you can use one CMA800R per channel of your headphones and make your rig a fully balanced set up. This is done by first of all putting the right interconnect into the first unit, the left interconnect into the second unit and then match the channels up with the interconnects from the DAC by connecting the 3 pin XLR cable from each channel, oh and switch the stereo to mono switch. Now I only have one CMA800R right now as when I got my hands on it, there were not a lot of them at all made (mine is in fact pre production) so I will not be able to delve into what happens when you use a monoblock headphone set up, but that surely is the dream! Owning just one unit and not monoblocking is not like having half a product or anything. Using it single ended with just one unit is still a finished product, too the fact that it is just what the CMA800 was and all it does is allow you to upgrade you system by purchasing a second one, if you obviously like what one of these does, I think that is more that understandable, and doesn’t everyone love that ability to one day upgrade, some thing that is of course inevitable, I mean how long can you wait before caving in and having monoblock amplifiers for headphones. It is just so awesome and although you might look at the price of two and think, hmm £1800, that’s quite a bit of money, the only other monoblock headphone amplifiers, the Woo WA234 cost £8000+ depending on the tubes you purchase with it so this is really alone in what it offers.



Questyle have used a more wide and shallow design with this, measuring 32cm across, 20cm deep and 5cm tall with roughly another cm in height because of the feet. It takes up a fair bit of desk space with its size in my case but that’s because its packed with high quality components and the size just shows it means business. The aluminum enclosure has a nice finish as well as being resonance conscious like any high-end design should be. On the front we start with the power switch, with its status being signified by a blue LED light, you then have another blue LED for when it is ready to output.  You then have another switch the lets you swap between the balanced XLR and RCA input and your choice is displayed on more LED lights. You then have two single ended headphone outputs, they don’t differentiate in anyway but I think it is a really handy feature, one I have used a LOT. For a start there is no quicker or more efficient way of a/bing headphones than using an amplifier with two outputs but more importantly it also has the grunt to drive anything to the levels and performance needed. It is also just nice to share the music and listen with a mate, whenever my good mate and guest reviewer Josh comes round it is always very pleasant to just both plug in and check out some new music. You then have the mono/stereo switch and 3 pin balanced output and then finally we have the ALPs volume pot that has great tracking, feel and smooth volume control, everything you want from a volume pot. Turning it around to the back of the unit we have the power chord connector, pre-amp output (something that could certainly be handy but not something I have used), balanced XLR input and then we have the 4 inputs alternating from RCA to XLR, which gives nice spacing between connectors. The overall construction seems tight and it has nice round flat feet that look like they will treat whatever is underneath in a stack gently as well as doing the normal, anti resonant stuff. You can also choose the amount of feet depending on how your set up is and what works best and you can choose 3 feet design or 4 feet like me. The biggest regret with the whole design is how stand out the screws are on the top, the are only small yet all 8 of them stand out like sore thumbs and it would be nice if they took just a lower profile, but I mean, this is an audio device so I am not going to get all down about some screws. The features please me, it looks like a serious piece of kit nothing has left a negative impression so far.



Moving on and lets talk what is suitable to use this with. Now it is an amplifier that is clearly made for working on a desktop rig (I know I am stating the obvious) and yes it can power the most hungry of them all. It laughs off high impedance stuff with 300 Ohms showing no trouble and the 600 Ohm T1 showing it’s very best. Next up are planar magnetic headphones and they are different ball game, they are very specific and no easy task and I have seen some “desktop amplifiers” cower at the task. Well, 1.1 watt into 30 Ohms (in single ended) is more than plenty and that shows when listening to my HE500s. I think we can safely say while synergy is a different matter, now matter how demanding a headphone can be, these will be able to power them. Now moving to the other side of the scale and as a test for a low impedance full sized headphone I gave the CMA800R a whirl with the fantastic Beyerdynamic T5p. With an impedance rating of 32 Ohms they are not a very demanding headphone in terms of power but they do upscale fantastically and rip apart some inferior sources and amplifiers. The CMA800R sings with the T5p, I mean this is a genius combination, I was not so much expecting this as I though the gain would be pushing a bit too high with it being 15.5 decibels and not variable but no, that certainly did not get in the way. However when the sensitivity ratings get higher with 16/32 Ohm IEMs that’s when the noise does start to kick in, we do get hiss and while the quality is there, listening wit hiss is just distracting and if your someone who wants a desktop rig for their IEMs (unless it is a Etymotic ER4S, Lear LCM-5 with Adapter or HiFiMAN RE-262 which are all high impedance), then this is probably not your best bet. Variable gain would have been nice but at the end of the day this is made to drive cans and that’s exactly what it does with no questions asked.



My listening set up consists of my iMac with Audirvana Plus as a transport, then through USB I go to my Rein Audio X3-DAC and then I use its balanced XLR output to the CMA800R. All cables are from the fantastic Charleston Cable Company. So lets talk about how this sounds….



To be fair the easiest way for me to get across how this amp sounds would to just simply say, it is amazing. I have tried my fair share of both expensive and well renowned amps and while I can not remember a lot of the sonic discrepancies of the models, I do know a lot of the time I walk away a little underwhelmed, be it if I have tried it with my own headphones or a model I do not own yet am very familiar with. Now nonetheless I would still say a lot of these are good amplifiers but just weighing in everything about them, I can not say they are excellent and in some cases they just don’t leave me listening to the headphones at the best level I have heard them. This has something about it that makes you think wow, this amp sounds awesome, even from the briefest of impressions it can draw your breath away. Now I would be doing a pretty lousy job at reviewing to just say this is an amazing sounding amp and the wrapping it up and I am of course going to delve deeper. I just felt it was needed to be said that if your not someone who is too big on all the little audiophile slang words I drop, I was still getting across how this amp performs. Now Questyle have clearly decided that they were not going down the colour the sound route with this because I don’t sense any additional warmth, brightness or coldness with this, it is like the name says, reference in the it delivers a nice balanced frequency response. Its also so very transparent that it has become quite a handy tool in reviewing DACs because it can show up what the DAC is doing shockingly well, I mean, it can make a DAC weaknesses a lot less forgiving than any other amp I own. When I mentioned the instant wow factor this amp gives me I think there are two more glaring reasons for this. The first is that the bass performance of this amp is incredible. If your headphones have any sort of capabilities in terms of bass then you have one hell of a bass show on your hands. It does this without increasing the quantities at all, I mean it is not bassy amp but what it does is maintains the amount of bass you have yet at the same time makes it tighter, punchier and just so solid, I mean the texture is like… perfect! The sub-bass performance is no different either, it just helps the headphone along to a stupidly visceral, belly wobbling bass performance, again not boosted, it just adds to the detail and feel of it, I guess a good way of explaining it is that it gives it a reality check, you say goodbye to the headphone bass and welcome on controlled sub-woofer bass. The bass really is nothing short of spectacular on this amp and it makes an impact from the start. The other thing that right of the bat will really hit you is the overall resolution and detailing, which I guess goes hand in hand with the transparency I have already mentioned. This is one of the reasons I do like having an amp that is not coloured in anyway has they can go artificial in the details with the likes of brighter amps have that extreme clarity effect while warmer amps sometimes just don’t deliver as much on the detail front and can be a touch veiled. Now the way this amp presents everything is so it is natural and resolving, it doesn’t push too hard to get the details across and there are just so many, they highlight every nuance, catch the linger on every breath and allow everything little part of the music be heard. It is a combination of both amazing details and real honesty with what it presents and this is a killer combination, it sounds so raw and real. Now while these are things you will be wowed at right from the start, they are just part of the make up of this amp, just a little of what it can deliver.



Now I cannot believe I am starting a paragraph like this but a potential “problem” with this amp could be the treble. Not because it is portrayed bad, technically poor or shown me any trouble at all. I say it because it is balanced, very detailed, superbly extended and does have a strong amount of clarity and sparkle that I guess synergy with some headphones that are a bit top heavy could not be amazing. This being said I have found the treble to be nothing but jaw dropping with anything I have used it with, including the treble sensitive Beyerdyamic T5p and HiFiMAN-HE500 whose treble easily gets sloppy. I mean it has great control but I do appreciate some headphone do want a warmer amp that has smooth and laid back treble, like my Graham Slee. This really is not me saying I have a single problem with the treble, that it is even slightly boosted or a tiny bit sharp because it really is not, it is just me trying to have a small bit of moderation in this review and trying to look at this amp from all angles. The timbre of the treble is incredible and the extension is something to dream about! Oh and do not let that put you off this with the Sennheiser HD800 because though I still have not used it with this, Questyle have told me that was the main headphone used in designing and it is just the most incredible pairing.



Another very important part of the sound is of course how it is presented and this is yet another area I am left very impressed with. It all starts with that incredible treble extension, which gives the sound a great amount of air to work with, there is a lot of space to fill and CMA800R uses all of it, spreads the sound round to where it should be, I am talking very accurate imaging here, and keeps the instruments apart. Instruments are clearly, I mean very clearly etched out, switching to a few other amps seemingly gives them blurred lines, this just presents them so tight and true, like someone has gone round the edges of all the instruments with a highlighter. You then have incredible layering, depth is used to a clear advantage and this has some depth. The overall soundstage is very expansive but I am not going to say that I have not heard some amplifiers do a slightly better job in terms of width, this really does deliver in terms of a full three dimensional package and when listening to a headphone that already has one hell of an open sound like the Beyerdynamic T1 on these the end result is getting very close to true speaker HiFi. Now I can tell you that all this thrown in the mix ends with a very musical sound. It is not in the slightest clinical or dull, it has sparkle, it has excitement, it is quick and snappy and it is just so clear. Detailed presentations in audio also seem to have a general sigma in that they come with a more empty sound, not so much body and a thin sound. This is also mainly a cause of that artificial sound that, “yes they are detailed but do not sound real at all”. Well the presentation of this is full, bodied, not thick as such but real, drums hit hard, vocals have true body and height and pianos have all the emotion and decay they should ever want.



It also has the ability to completely transform headphones with the sky as a limit. What it does to my Sennheiser HD580 is really miraculous. They were one of the first headphones I bought when entering the hobby and I picked them up at a very cheap price, a bargain I must say. For a while they were my most listened to headphone with my Objective 2 amplifier but when I got into reviewing and my collection grew, they sat on my headphone wall rack gathering dust and hardly getting used other than testing out new amplifiers and even then it never impressed me to great levels.  Now paired with the CMA800R I would say this is one of the best headphone set ups I have heard in my life, up there with the greats. I feel like I am listening to a very expensive headphone and not a model from 1994. They turn into a headphone that has sublime detail retrieval, a HUGE soundstage and a deep and powerful bass response as well as great dynamics from top to bottom. It is funny because of all the headphone I have tried with the CMA800R this has been my pick for synergy, and manages to put the HiFiMAN HE-500 and T1 to shame in some area, something that is not really a normal occurrence. The HD650 being a very similar headphone to the HD580s also really change up a gear, in fact I think I do slightly prefer the HD650 off the amp but both the Sennheisers go from being a more entry level HiFi headphone to a true beast of a open backed headphone and one that could be part of an end game rig I think that is a big deal.



Now I think my most worthy amp in my collection for a comparison is the Graham Slee Solo Ultra Linear. It does not quite have as big a price tag at just over £600 but is still not a cheap option and in the US would still be in the 1000 USD plus price bracket. It is an amp like the Graham Slee that really emphasizes the detail that the Questyle brings to the table and this is mainly because it has a more warm sound signature with a spongier mid-bass and subtle but slight sub-bass roll off in comparison. While a laid back amp is easy going, not fatiguing and a sweet listening experience, it just clearly lacks that speed, resolution and that amazing separation and distinction the Questyle has between each and every instrument. Changing amp is also like sealing a pair of open headphone where soundstage is compared because the CMA800R is just that much wider and deeper, it really is noticeable. The CMA800R also has more presence in the higher frequencies, not because it is boosted but because the Slee is quite relaxed in them ranges and also has a hint of a roll off and not as much air.  The Slee also seems to have a more forward midrange and it also seems to capture the emotion in a different way. Listening to JD Southers “The Sad Café” and the CMA800R does much better job on using it amazing details to convince you of all of his emotions when singing the song yet I think the more forward Slee shows the strain in the voice of the likes of Adele when she is belting out one of her numbers. However this does sometimes cause the Slee to get a bit over excited while you know the Questyle will always keep calm and stay in control. In truth with the whole higher you go the smaller the differences argument I am actually quite surprised with how the Questyle exerts its authority over the Slee because it truthly is so much better of an amplifier, even if it is a different sound signature.



All other amplifiers in my collection are completely blown away by the Questyle, like serious no contention, so in terms of comparisons I do not have anything else worthy and the Violetric I last reviewed is no longer with me as that would have made a bit more competitive of a comparison although from memory using it with my headphone the only serious pro it had other the Questyle was the variable gain meaning it was great with IEMs as well but in terms of sound I do not remember it stepping up to the Questyle. The Beyerdymamic A1 is another amp I have used extensively and that was something that is both as expensive as the Questyle and also cannot match it. When using it, I did not like how it paired with any headphones apart from the T1 and impressively the T1 paired with this just as nicely, yes things were a little different but they were as good and in some places better with the Questyle so there is again, not much competition there.



Now as far as a recommendation goes, well I say it a lot these days I can not feel comfortable instructing anyone to by anything as these products I review are very expensive but if you have given you self, around a grand or more for a new headphone amplifier then, this is where I would point you without a doubt. Although I have not been able to offer detailed comparisons, I have tried a lot in the price range and this just differentiates itself from the others when it comes to overall sounds, versatility with headphones, power, function and of course upgradability. I think upgradability is a key word there as because you may only have the budget to get one CMA800R, no one in this hobby is ever finished the path of upgrading, you will always want to improve things one day and I think this gives you a great option with that. You buy the amp, enjoy it for however long and when that need to upgrade again comes around, you can double, go fully balanced and move things up a level. This also has next level synergy with 300 Ohm headphones and more importantly those of Sennheiser, if you plan on using an amp with a HD580, HD600 or HD650 then this will turn them headphone into true top class stuff. I guess what amp you get will be determined by what you want out of one and personally I value overall sound top. This clearly delivers in that regard, the sound is brilliant and because it does not colour the sound and is so transparent a detailed it ticks my next box in being versatile. I want it to work well with new headphone purchases and with it not struggling to drive anything and having a very easy to work with sound, there is a high chance most of your current collection and collection to come with get on very well with the amp. Lastly you want the proof, you want to see it using the most expensive and highest grade parts like this does and you want to see the measurements that are as close to perfect as be and just look at the frequency response and total harmonic distortion for example, damn this measures so well, you could almost say too well! Questyle have stormed into the market and with products like this they are going to get themselves well known quickly, they have taken a long time with this, 6 years of work and it has paid off and I think in the years to come they are going to be one of the big names everyone looks at with pure want. This is of course if they can keep delivering as well as they have with the CMA800R, a truly amazing headphone amplifier, one that leaves a smile on your face and lets you know how darn good it is from the moment you let yourself have a listen.



Lastly I want to say that hopefully this is not the end of this review or that it is merely a part 1. I am hoping that Questyle are in full production I can get a partner for me CMA800R and then we can take a journey into a full balanced set up and see what joys come with that!

Sonny Trigg