Harness The Power

In my original CMA800R review I did in fact note that it seemed a bit too powerful for lower impedance headphones. While sounding fantastic with the likes of my Beyerdynamic T5p, it was hard to get over the noise in the background. Even though I knew we were getting more power in this configuration I was hoping the improved implementation of the amp could lead to it being quieter. Sadly that is not that case and this amp still does not suit my top tier headphones that have a lower impedance and higher sensitivity rating, namely the aforementioned T5p and the recently released Enigmacoustics Dharma that has no need for such a silly impedance of 26 ohms. At least the Beyer can justify its low impedance being a portable branded can. Now the Dharma is easily not as much of a hiss feast as the T5p but I still can’t recommend the pairing, even though other than that the sound is good. Unlike my Tektron Head Amp that even hisses with my HD800s, this is perfectly quiet with any headphone properly made to handle some power and to use at home, examples including the HD800, ZMF Blackwood and Audeze’s LCD-3.


Your Sennheiser’s Deserve This

This amp is at one with HD800s, it really is quite simple. They used that headphone for testing when making this amp and even named it after the headphone. I actually didn’t have one for the original review but marvelled at its performance with the HD580/HD650, which has a matching 300 ohm impedance as the HD800 and not too long after I ended up getting a HD800 which has been my reference ever since, along with the CMA800R. This combo has been a real god send for me, letting me review DACs and cables with ease due to its amazing transparency and giving me the upmost pleasure when listening in my day to day life. The sound is phenomenal and I TRULY believe that these monos paired with my totaldac (and Double Helix Cables) is one of the (if not THE) best HD800 systems in the world. It is mind blowing. Please let me add as well, I have heard quite a few different configurations of the HD800. There is no doubt that with amplifiers synergy goes along way and as far as i’m concerned nothing has been getting on better with these amps than my HD800 and the HD800’s get on with no amp better than the CMA800R’s that I have tried.


Sound Signature 

I see a lot of talk about which amps suit HD800’s. Most people seem to think that is a typical tube amp or something that is warm, euphoric and a little bit darker. Personally I do not subscribe to these ideas because that is not what the HD800 is about and it shouldn’t try and be changed. I personally want a forward treble, great clarity and a fast bass but more importantly I want control, dynamics and coherency, they are something that not a lot of amps can manage. While the treble should not be brought down, it certainly can’t sound ragged or harsh.  These are all principles that I think Questyle agree on when it comes to driving the HD800.

When it comes to listening to them with the HD800’s I feel like they are very revealing amps without much or any colouration. It was not as warm as the new Moon 430HA, nor did it have as syrupy treble. The Moon may have lacked a touch of refinement in comparison but did a lot better in portraying energy and dynamics, speed and was certainly more neutral.

Tonally the Questyle Monos are similar to a single unit and we will touch more on the differences in the next section but to summarise I would say that it is a fast and neutral amp with just over average body thickness. While Innerfidelity have recently been very happy with the neutrality of the Moon amp, in my collection the CMA’s certainly seem the most neutral culprit.

Bass is not huge and seems snappy on the decay, keeping things punchy and also present a more crisp sound instead of warm and relaxed one. The measurements show a very slight boost at like 30hZ and while I don’t think that really means anything being so deep these have no problems with extension and while bass is quicker, it is still very much whole. The midrange and treble keep the same tune and they seem to have that same clean and energetic vibe to them. This is quite a forward amp at times, it is certainly not as mellow and my Tektron tube amp for example, or even something cheaper like the Graham Slee SUL.

Something that certainly seems a special trait since I have gone mono is the precision and space between instruments and also to give anything reasonably hard to drive a dead black background. Overall, this is a spacious and fast amp that still manages to remain bodied and has no problem revealing the music, hence it is so good for me when it comes to reviewing DACs and finding the smallest of nuances between them.

Is Two Better Than One?

Now this is a very big question as while there is no doubt the monos sound great, is that second unit worth the extra money. I make you right if you have been wondering that, because I felt the same, a single unit was great and how much mileage will you get buy doubling the cost. I actually find that going back to a single unit gives the sound a shift to the brighter side, but not in a way that there is more treble but one that has more decay and a sharper finishing touch. It is a little more metallic and hard, and while a pair don’t lack treble presence, they seem 10x more robust and articulated.

The sound is also smaller. It doesn’t have the width, the sense of space and precision in instrument separation. Everything soundstage related just seems better when using two, no matter what can i’m using. I want to add that when comparing the two configurations I am using the same everything from DAC to cables, just using an adapter when needed.

Pushing further on the quality difference in the treble, I find the same with the rest of the sound the midrange is slightly more forward and balanced, the bass seems tighter and more refined. Now your mileage on the differences may vary from headphone to headphone but I was surprised that even the HD800s got an obvious boost in performance. That being said, my ZMF Blackwood, which are not easy to drive seemed to get the much more clear cut changes from their reaction to the additional power. In fact one CMA would not be something I would recommend for these headphones but two pairs nicely.


I Think So!

I will admit that for me there was a lot of hype to getting a second unit, almost two years of wait and a system waiting for it to slip in.  That just means there was more pressure on it to deliver, it had to be worth the wait and boy it was. It has certainly pushed a solid amp to a top tier one and come on, there is something simply cool about having mono block headphone amps. In a completely overkill way no doubt! If you are a HD800 owner this is a must have and there is a very good chance it will get on with other cans you have as well, from my brief demo in Munich I think the LCD-3 is another top match. That being said things like the Enigmacoustics Dharma and other lower impedance headphones are just a no go, there is too much gain and noise for that and while the sound is not necessarily bad, it just isn’t the listening experience you deserve for the price. Other amps are almost as good sounding but are much quieter with the likes of the Dharma and T5P.

For me the biggest shame with these amps is the new official UK price. It is not going to stop me recommending them but is an inflation from the original price I reviewed this at back when you had to import it (I know taxes would cost a little then as well), less hassle but more money. When buying something I always end up making hassle to get it cheaper so for me this doesn’t seem great, but I am all for Questyle getting worldwide exposure, especially here in the UK!

Sonny Trigg
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