Competitive class D amp suggestions


I have been Class D fun since a few years ago when i bought my first class D amp. I like the concept, in general, and all the attractive features of this class of amplifiers. I tried 4 different ones, currently i  stayed with one of them that i consider to be the best among all four amps. I do enjoy and like it. At the same time,  my 5 watts SET amplifier (with more than 100 times higher distortion according to the specs) gives more natural and (surprisingly) notably cleaner sound (THD of the class D amp is 0.001). The soundstage  of the class D amp is not so bad but that of the tube one is still better.   

I remain attracted by class D amps though. 

Any fresh suggestions on reasonably priced class D amps (i mean excluding  non-reasonably priced class D amps, e.g., Merrill amplifiers)?

Any comments on non-reasonably priced class D amps are also welcome (so far i was not able to audition many class D amps and am curious if there are some which could really compete with Class A). 

128x128niodari

@niodari Red and blue track the two stereo channels.  In a well engineered component, they should pretty much overlay; more than a little divergence is indicative of a problem with components, construction, design, etc.

@niodari 

I suggest that Atmosphere and AGD  amps may sound somewhat similar to Cherry, but cannot be sure of course.

only one way to really find out, right?  😉

The AGD room at Florida Expo was one of the best sounding rooms at the show. And the amps are really works of art; gorgeous.

The Aavik is another class D beast, but on the expensive end.

I've read many good things said about the NAD.

​I used the LSA GaN Voyager  in my main system for a few days. Not surprisingly, it didn't sound worse in the main system, which is a good characteristic. At the same time, the main system revealed some technical problems related to the amp. I noted this before in my second system as well but I suggested that the problem could have been in the preamp. 

First, the amp just does not sound well  with the balanced inputs - there is a quite notable lack of the middle and high frequencies with the balanced inputs ( i tried two different quality  balanced cables). Fortunately, one of the RCA inputs has no such problem. 

Second, a quite strange thing happens. With both XLR inputs, the left channel is too weak.  And with both RCA inputs the right channel is too weak. I mean, even if i stand in front of the speaker, the sound coming from the other speaker is dominant. The preamp in my second system has the balance control, so this issue was somehow "settled" by reducing the volume in the normally sounding channel by about 40%. The T&A DAC/preamp in my main system has no balance control, so it was just impossible to use the amp with either XLR or RCA inputs. ​Then i used the rear switches to put the right channel in XLR and the left channel with RCA modes . This was the only way to achieve a more or less balanced sound. 

Third, i think the amp has some phasing problem. Apparently, it is made out of phase. But when I swapped the positive and negative speaker outputs, the amp remained out of phase. Perhaps, this is not a big problem but something may also be wrong with this. 

Based on my small experience with the combined XLR-RCA auditioning in my main system (thanks to the rear amp switches that permitted me to use such an option), i think there is nothing particular to complain about  the sound quality of the amp (judging analytically). At the same time, there is no point in comparing it with my SET tube amp that just sounds more real, full and alive. This can be subjective. But perhaps, not. Just take one of the CDs I used to compare the SQ of the two amps. It is Keith Jarrett's "Buy buy blackbird" (hey @jjss49 !). It is a particularly well recorded CD. Although it is a studio album, one can feel the studio environment and the musicians on each of the instruments, just as if it were a live recording. The SET amp gives this feeling, the Voyager does not (so far as it is  now). 

Perhaps, the Voyager may still improve (it should have about 110 hours of burn-in). I will be able to judge once I get it back from Underwood Hi FI. I am going to ship it for repair today. 

 

@niodari 

Here's the measurement of the Technics SU-G700M2, which may not be exactly a class D amp, or a GaNFet amp, but which is something close.

As you'll see, some of the higher order harmonics are higher than one often sees, and normally you only want to see the second and third harmonics around that level.  John Atkinson commented:

"The fifth harmonic in both channels, the seventh harmonic in the left channel (blue trace), and the ninth harmonic in the right channel (red trace) were almost as high in level as the second and third harmonics. Although these harmonics are low in level, lying between –80dB (0.01%) and –70dB (0.03%), they could be audible at high listening levels in the region where the ear is most sensitive."