AIYIMA A07 Premium TPA3255 Power Amplifier 300Wx2 HiFi Class D Amp Mini 2 Channel Stereo Amplifier for Desktop Bookshelf Speaker Home Audio Theater System with DC 32V Power AdapterClimatePartner certified

This is an amplifier that punches way above its price range and size. It is well built and looks great. It has tested very well for its technical performance (see Audiosciencereview's test report) and that is reflected in its sound performance. I am using it to drive Elac 6.2 Debuts, and it has plenty of headroom that I will never need. And I am using the 32V 5A power supply option, which means I am barely powering it to just over half of the amplifier's output potential.The amp runs very cool when driving my Elac 6.2s. I am using a Schiit Modi 3+/Magni 3+ stack to feed the amp.To take the sound to the "next level", I tried several op amps including one that was recommended by an engineer at Aiyima in a paper called "The OP Chip Can Use on AIYIMA A04 & A07". Obviously I tried the NE5532 that comes with it. This sounds great as it is. I tried the LM4562NA. This offered some improvement. I did not leave this one in long enough to characterize it, only that the sound was "better". I tried the OPA1656, which I feel actually degraded the performance. The op amp that made a significant improvement is the OP275GPZ. This is one that is recommended by the manufacturer as an op amp that offers "Better resolution, low frequency and sound field than NE5532". I found this to be very much true. I think by "sound field" they mean "sound stage" as that really did open up. There is a clear improvement in resolution. I also found the treble to be more refined which was not expected from the description from Aiyima. And it also took "boxiness" out of the vocals. I don't know if the boxiness originated from the amp or my speakers, but the 275 cleaned up the vocals and they are now simply excellent. If op amps were free, I would try some others that the paper recommends. But given that they are not, and I feel I have hit on one that yields a big improvement, I am done searching. Any others will either most likely be a step back or just offer marginal additional improvement.This is a great amp as it ships. Since the input stage op amps are socketed, you have the opportunity to "roll" them to adjust the sound to your liking as I described above. For me, I found the 275 to be a phenomenal choice.Based on my experience, I highly recommend this amp!

Got this as part of a cheap system for my bedroom. I have only listened through the equally inexpensive Sony sscs speakers but the sound is fantastic for the money spent. I want to listen with better speakers to understand the limits of this amp but I am already happy if this is the best it gets.Good: Great sound top to bottom. Decent imaging that doesn’t go outside of the speakers or have much depth but that might be the speakers. Played for hours with the volume at 50% and it did not get noticeably warm. Dead quiet when no signal is coming through. Lastly there is a mono 3.5mm out on the back that I have hooked up to a sub. There’s no filter or control on it but it seems to work fine.Less good: these are nit picky because not much is wrong with this amp. The speaker bindings have small openings for bare wire. I got 14 gauge wire and it was difficult to put in the hole. I bought banana plugs but haven’t tried them. Also the volume control is logarithmic instead of linear, the first 50% of knob travel is only 25% of the volume. This is a design decision and is very common. I just prefer linear. Online reviews say that the op-amps in the circuit are clones or fakes and don’t sound as good as the real ones. No idea if this is true but it is cheap and easy enough to swap them so I plan on trying to see if there is a difference. It still sounds great so 98% of people won’t care either way.Summary: A great deal for the money.Update: October 2024. The amp is still working great. Strong output, good sound. I changed the op-amps with I remember to be opa2134s. Hard to compare without having 2 amps to switch between. I think the OPAs have a tiny bit better imaging but the difference is so small that I wouldn’t do it again. It is fun to tinker though.

I had a couple old speakers laying around and was looking for a way to use them again. I came across this amplifier after reading glowing reviews on audio science review. The speakers I am using are a pair of Fisher XP-6 which are 8 ohm speakers. I used to have these hooked up to a Pioneer receiver a long time ago and I don't remember them ever sounding as good as they do with this amp. This amp has no trouble driving these speakers, the sound has no distortion, or clipping, and very full sound. There is no hiss or static from this amp. There have been comments about increasing the power output of the speakers with a new 48volt 10amp, but for now the included 32V 5 amp adapter is more than adequate. There is a clear separation between each channel, just make sure its making good contact with the outputs.I like the weight of the volume knob too, it feels very solid, not cheap. I usually only keep it about a quarter volume. This amp gets loud. I haven’t even turned it to max volume yet. I am just amazed at the size compared to older amps I have had. So far it hasn’t gotten too warm which is a great feature of Class D amplifiers. Its also great that it has the option to daisy chain the inputs together and expand how many speakers you have together.I am looking for a better source to provide to it but for now I had an old galaxy s5 laying around which I use with viper4android to tune the 3.5 mm jack output. So far the sound adjustments I have been able to make improved the music even further. It has been a real joy over the last couple of weeks to listen to music thorough this amplifier. I’m hoping soon I will upgrade my source.I am blown away by this amplifier and highly recommend that you try it. The form factor is amazing, and for me pairing it with an old smartphone I had makes it way more functional than that bulky stereo receiver I used to have.