AIYIMAA07 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 Adapter (A07)ClimatePartner 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!

I bought this little amp, a Bluetooth receiver, and a powered subwoofer so that I can put my pair of Blueroom Minipod speakers to use which I had lying around. I mostly use this setup for playing Spotify from my iPhone through Bluetooth. I got the AIYIMA A07 on sale for about $65 and the Bluetooth receiver (BlueDento B1 aptX HD Bluetooth 5.1 receiver) was about $35. I also added a 10" powered subwoofer (Monoprice SW-10 150 watt RMS) which purchased from Monoprice for ~$90. The setup gets pretty loud without any perceptible distortion (with volume turned up to about 1/2 way to full) and the sound quality is surprisingly good! It is less than 300w per channel because of the power supply that I have. But, it is plenty loud, believe me.The thing that I like the most about my setup is that the whole setup takes up no room at all and is out of the way so that you don't even notice it. It occupies a tiny corner of my desk and the speakers are hanging on the wall with the subwoofer under my desk. I am loving the sound! There is no sibilance. I can't believe that this cheap little setup sounds so good! I mean audiophile quality sound! The sound staging is fantastic! There is a lot of realism. With my setup the frequency spectrum is well covered from about 50 hz - 20khz. When listening, I sense a lot of space between individual instruments and voice and near absolute silence when there is no music content. I leave it on 24X7 because it doesn't use much power when there is no content and whenever I want to play music, I just turn on the Bluetooth on my phone or laptop and off I go, instant music. I also control the volume digitally from my phone or laptop as the Bluetooth transmits original digital content and the DAC which is inside the Bluetooth receiver does the digital to analog conversion so, be sure to get a Bluetooth receiver with a good DAC chip in it. I have the Berwyn chip which is pretty darn good.

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.