A70 Mono Amplifier with PFFB TPA3255 Audio Receiver Class D Amp

Electronics engineer's review will be coming soon (tm) As a consumer, the A70 just works. It is a great amplifier with some really cool features I never knew I needed. As far as I can tell, it meets or exceeds all its specifications for TDP, power output etc. I will be evaluating this in more detail under different loads at a future date so for now I will cover more of the cool features: 1. XLR is a nice to have. I don't personally have any in my setup but occasionally I have used it for odd or specific setups. 2. The +6db is REALLY nice. Some audio sources are really quiet. The worst offender is an LG TV that automatically drops the volume every 30 minutes if you set it above a certain level in the UI. The trouble is, the TV doesn't actually know how loud the room is so this may be going from a comfortable volume to nearly silent. The +6db allows you to get the full range out if this amp with such sources. 3. The built in crossover is cool. Not used as I have a full equalizer for room calibration but I can think of times it would be useful. 4. The 12V trigger is awesome! I cannot wait to build a custom controller for this that allows it to be switched on and off with the rest of my setup to allow for energy savings. I really only have two gripes: 1. AIYIMA already has a product with the name "A70" which could be confusing. They also advertise this as being used for 7.1 surround setups, but having 8 of this seems like it would require excessive tinkering to get a room to sound good compared to an all-in-one receiver that is programmable.

This amp does a pretty good job. The power supply it comes with is a quality item that delivers it's specified output, and can even supply more than 8.3A. I tested it on my electronic load, but my load is 400W max, which this supply delivered. That was a nice surprise. Chinese supplies I've bought on Amazon before usually provided only half their rated output current. Can the amp deliver its speced power? The ratings don't specify RMS, continuous power, so perhaps it can provide 600W for tiny peaks into 2Ω, but it can't output a sustained 600W. With a 2Ω load, the power supply goes into protection and shuts down at about 315W RMS. With my bench supply, it can deliver about 450W. It draws about 10.2A to do so. But most home subs are 4 or 8Ω, so those unspecified ratings are more useful for many of us. I can increase the output at either 4 or 8Ω until the output waveform begins to distort without the power supply shutting off. Max power at 4Ω is 256 Watts RMS and it begins to clip with 8Ω at 170W. It only draws about 5.5A at clipping, so there is plenty of extra power in the PSU for peaks beyond the RMS ratings. This amp has unusually low input sensitivity. I connected my signal generator to it with an unbalanced TS 1/4", and to fully drive the unit I had to send 8V peak to peak. The rca input has a +6dB gain switch that should almost always be turned on when using this input.

I'm currently using two of the Aiyima A70 mono amps that work great when paired with Dynasty ProAduio PX2 pre-amp. I wasn't able to run amps at full bore due to sound was too loud. No joke. Previously, I was using a Douk tube preamp which until it went out within 3 weeks of use. I thought sounded good until I decided to paired with the PX2 preamp, and they work really together. The Aiyima is clear and articulate as any full size amp I've had used before. I'm talking about NAD, Adcom, Hafler or Yamaha.And I had them cranked to just over 1/2 where the sound was too loud with no distortion or breakup. No Bluetooth with this amp. I was surprised at the headroom given, and the attack time was spot on. I'm not joking. But how long with these last, no idea. I got these new on sale, one for $118 and the other was $85. I highly recommend, will fill a room 18'x15' with no issues and volume to spare. So far a strong 4.5 amp!

Like other comments here I failed to this amp to work properly in subwoofer configuration (switch on bottom). I tried both the RCA and XLR input. Aiyima A80 is my source, though I tired a second DAC straight to the A70 as well. It seems like the input gain is not set properly to match the output level of the rest of the system. Using an oscilloscope I did verify you could get to the ~200w output (provided power supply is 240w) but I had to set my A80 to +10 db on the bass, volume all the way up on the A70, and the +6db switched on the RCA as well, and turn the A80 ALL THE WAY UP. Tried a different passive subwoofer. Verified using REW that with normal listening levels ~76 db on my main speakers the sub would never get past 65 db @ 1m again with everything turned up to max. I also used REW to verify my x-over point was rolling off at ~90 Hz. 3 of 5 stars because it does technically work, but not at all to my expectations based on reviews.

First of all must explain how this amp works. There is a switch on the bottom to set it for full range or subwoofer. When set for subwoofer duty, the front panel knob on the left adjusts the low pass frequency. Great for adjusting by ear while listening to music or test tones. Perfect for use with a passive subwoofer. I see online reviews that complain about the fact that this does not have a high pass filter to use as a full range mono amp. That is not its best use case. I am using mine with a 12" passive subwoofer I built myself and it works great. I think it is a much better amplifier than a lot of the low cost plate amplifiers out there and the cost is very reasonable. I love that these come with 48 volt power supplies instead of the 32-36 volt supplies that some of these low cost amps come with. That way I don't have to spend more money to upgrade to a 48 volt supply. I will add that this mono amp integrates well with the Aiyima A20 stereo amp which has a high pass filter and a subwoofer out. Last note - if bottom switch is set for full range, there is a small knob on the back that sets the low pass frequency for the subwoofer out on the A70. I really only have one possible negative. This works best with a high efficiency 2 or 4 ohm sub - something that can do 90 dB @ 1 watt. My 12" sub does that easily. If you have a small low efficiency sub, then this amp may not produce enough volume.

Clear sound. Dynamic amps. I've owned a number of these Class D amps. This is my favorite.

This is a mono (1-channel) audio power amplifier, but provides one full-range speaker 50-watt powered low-level output, and one subwoofer passive (mono RCA) output. I hooked it up in concert (Daisy-chained) with another 2.1 channel amplifier, and it sounds amazing, when I synced the timing.

I bought these to replace plate amps on an older pair of Definitive Technologies BP7006. I bought one for each speaker and they have plenty of power to drive the 8” woofer. Versatile connection options and tunable crossover make these even better than the original amps for these speakers. Runs cool and takes up very little space. Great build quality. Highly recommend.

オペアンプを換装したら大化けのアンプになった。

Tolle kleine Mono-Endstufe. Verwende zwei davon seit gut 1 1/2 Jahren zusammen mit einem WiiM Ultra im Wohnzimmer als kompakte Stereoanlage. Das ist eine für mich super passende Kombination, die viel besser klingt als der Stereovollverstärker zuvor. Gepaart mit einem Plattenspieler und zwei soliden Standlautsprechern ergibt sich ein kompaktes, gut klingendes Hifi-Setup.

Come al solito ho aspettato un pò prima di recensire. Che dire,lo sto usando con l'impianto HT in mono su un subwoofer con 2 altoparlanti 4 ohm da 25 cm messi in parallelo tra loro. L'apparecchietto,per le dimensioni, se la cava egregiamente: pilota il subwoofer alla grande,senza minimamente riscaldare. Si, lo consiglio!

Manque cruel de punch. Incapable d'alimenter un sub 12'. J'ai dû le retourner. Sinon objet joli.

Great amplifiers. I have tried quite a few amps over the years and these perform very well. The price to performance ratio is truly impressive. The A70's provide a wide soundscape with excellent detail retrieval and separation between the notes with a slightly laid back sound that I can appreciate. I also tested them using a set of older JBL speakers that have some slightly "bright" tweeters and I found that these Aiyima A70 Monos paired better compared to the Fosi V3 Monos I had connected previously. I am constantly very impressed with their sound quality. I then connected a powered Subwoofer and to my surprise I found that the Crossover knob on the back of the A70 worked better than the Subwoofer's Low Cut knob. I used a small screwdriver to make micro adjustments when dialing in the Low Cut on the 'Sub Freq' dial on the rear. A great feature that I was not expecting to use. I opened up the amp to inspect the build and immediately noticed that the A70 has a bigger and better heat sink compared to my Fosi V3 Monos, and they do indeed run cooler. There was plenty of power for my speakers and I only noticed a tiny amount of distortion at really high volume. I suspect that they may not sound quite as clean with really power hungry speakers at really high volume levels. I would easily recommend Aiyima A70 Monos and I am happy I bought them! (streaming Tidal, SMSL D0100 DAC, Mogami XLR Cables, 2 x 48V 5A GAN power supplies).