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 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 didn't expect much for this amp. I have klipsch bookshelf speakers and a active sub woofer on my computer for music. I had a good Autosource amp that I have had for several years and fairly large. It decided to take up smoking and went out in a flash. It did heat up when it was on.This little amp is amazing. It was easy to hook up and has a connection for my sub woofer. There are no adjustments, but the clarity of the sound is better than my old amp. It is a little strong on treble, but my sub woofer fills in the rest of the sound. I played music for several hours and the amp did not heat up. Takes up very little space. Smaller than I had expected, but a great value.

Overall, this is an impressive little amplifier. Sound quality is very good, and the design is acceptable. I will probably get another one from this manufacturer.Tested onKlipsch R-41MKlipsch SB1Alesis Monitor OneThe sound quality is very good even at higher volume. I did get what sounded like a little bit of ringing in the high frequencies on the Alesis Monitors. I was unable to reproduce this ringing using my Class A/B Sony amp. To be fair, it was only on one song that has a lot going on in that range.PROS:Sound quality is very good.Very Little Heat when running at near full volume.Offset binding posts are a nice feature. They make it easier to put wires on it.Upgradeable Op Amps due to socketed chips.Very compact.The volume control is very nice. It is a click type potentiometer.Pre-OutCONS:Binding post are pretty much garbage. They don't support 16 gauge wire. If you are using this with larger wire get a set of banana plugs, don't mess with the binding posts.Not anywhere near the 300x300w that they claim. With the power supply included, maybe 75x75WI very much dislike the toggle switch for power. I think a push-button would have been better. Person Preference here, but it just makes it feel cheap.