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AIYIMA A70 Stereo Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 12 3.5%
  • 2. Not terrible (postman panther)

    Votes: 37 10.8%
  • 3. Fine (happy panther)

    Votes: 171 49.7%
  • 4. Great (golfing panther)

    Votes: 124 36.0%

  • Total voters
    344

amirm

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This is a review and detailed measurements of the AIYIMA A70 stereo class D amplifier. It was sent to me by the company and costs US $190 with 48v @ 5 amp supply. As tested with 48v 10amp GaN supply, it costs US $220.
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Review.jpg

As you see, the A70 comes in vertical desktop configuration. Controls are easy: push the button for power up and again to cycle between XLR and RCA inputs. Hold it for a few seconds and it goes into standby. Back panel shows nice inclusion of balanced XLR inputs:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced back panel GAN power Supply Review.jpg

Yes, that 10 amp brick is the mother of all external power supplies! :) At 480 watts, any heat dissipation would be challenging given the sealed box. Use of GaN transistors seems to have enabled high efficiency as it hardly warmed up during the testing. The amp's heat source is on the bottom. I wish the feet were taller to allow better convection cooling. Fortunately that area didn't get too hot in testing.

Nice to see trigger input to allow one button power up of the audio chain from the source. We also have a sub output wit variable filter output (yes, it is controlled by the volume setting).

Diagonal speaker terminals help some to fit beefier speaker wire termination.

There is a switch to add 3 dB of gain to RCA input. I didn't realize this until after testing. It is a smart move as the gain otherwise may be a bit low for some people.

The A70 is one of the few TI TPA3255 chip based amplification utilizing post filter feedback loop (PFFB). This should get rid of load dependency and improve linearity by dialing out the distortion from the output stage. Let's see if that is the case.

AIYIMA A70 Amplifier Measurements
Let's start with setting the volume to max using XLR input (all testing with 10 amp supply):
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Measurement.png

We see a nice boost in SINAD as predicted, landing the amplifier essentially in our "excellent" category:
Best budget stereo amplifier review 2024.png

Best budget stereo amplifier review zoomed 2024.png

RCA input has fair bit lower performance but still above average:
AIYIMA A70 Class D Stereo Amplifier with PFFB RCA Measurement.png

Note that I adjusted the volume down to 25 dB per my recent standard of testing amps (used to use 29 dB).

Noise performance is excellent:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced SNR Measurement.png

Despite its lower gain with XLR input, you can still reach full power at 3.3 volts which is well below nominal 4 volts we see out of majority of DACs. So I am good with that.

Let's jump into frequency response as that is the other big deal:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Frequency Response Measurement.png

Nice! We see a bit of frequency dependency but it is outside of our hearing range.

I set the subwoofer output frequency to the lowest and measured this:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Subwoofer frequency response Measurement.png

I don't know how this is useful for anyone....

Crosstalk is extremely good:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Crosstalk Measurement.png


Good performance numbers give way as you go up in higher frequencies in multitone and especially in 19+20 kHz IMD:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Multitone Measurement.png

AIYIMA A70 Class D Stereo Amplifier with PFFB balanced 19 20 kHz IMD Measurement.png


Let's see how much power we have:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Power into 4 ohm Measurement.png

AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Max and Peak Power into 4 ohm Measurement.png


That's a lot coming out of this little box. We are talking nearly 360 watts total. 8 ohm output is naturally lower:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Power into 8 ohm Measurement.png


Edit: as noted, performance does degrade above certain frequency:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Power into 4 ohm vs frequency Measurement.png


My reactive load doesn't like these bridged amps. The issue seems to be in one channel so I left that disconnected and drove only one:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Reactive Voltage Measurement.png

The amplifier is specified down to only 4 ohm but seemed robust enough to even handle 2 ohms, albeit with a good bit of voltage drop. Translating the above into watts we get:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Reactive Power Measurement.png

For those of who want to use these amps in mono, you now have that information as well.

There is likelihood of a turn on "pop" but turn off noise is completely eliminated:
AIYIMA A70 Class D Stereo Amplifier with PFFB balanced Power on Noise Pop Measurement.png


Finally, amplifier was essentially ready to go on power up:
AIYIMA A70 Class D Stereo Amplifier with PFFB Warm up balanced Measurement.png


Conclusions
What a journey to have watched in these "chip amps." We have gone from $30 to $40 amplifiers with horrible performance to above average in less than $100. Load dependency remained though and so many of us pointing it out, we finally have a solution to that as well. Alas, cost has increased so we are not talking about a fast food meal but one at a nice restaurant. You have to decide now if the extra performance is worth it. It is to me as an amplifier doesn't obsolete so might as well get a good one and sleep easy.

I am happy to recommend the AIYIMA A70 stereo amplifier.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
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Thanks for the review @amirm.
How does it behave with multiple frequencies vs power?, you have added a test for other amps for the same.

Nevertheless, it looks pretty good for the money.
 
I don't understand what the sub out-graph means. What is RMS level?
 
A70 has started pre-sale, and you can get a 10% discount for pre-sale.
 
Not excited, but a good move in the right direction.

- Single ended input is worse than A7 Max, Fosi V3 & ZA3.
- Subwoofer output practically unusable for most users. Regular active stereo line output will be a much more usable solution that can also be used to connect a subwoofer.
- 10 Amps GaN PSU brings nothing to the table. The Fosi V3 with their "ordinary" 48V/5A PSU has more power in 4 and 8 Ohms and is cool to the touch in normal operation.
- Price wise, it is too close to the Topping PA5 II territory, but the measured results are a joke, in comparison. Apart from the raw power that is the inherent difference between the TPA3251 and TPA3255 chips inside these amplifiers.

I'm eagerly awaiting for PFFB answer from Fosi. :)
 
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A70 has started pre-sale, and you can get a 10% discount for pre-sale.
And how do you get 10% discount?
 
Just bought an open box Topping PA7 for $270. Should I return it and save $70?
Other than the 30W difference, I don't see how I'll be able to hear the difference between the two...
 
Keep it, buy the aiyima, compare it, sell the worse one to a buddy for a deal.
Open box is not usually b-stock, or returned stuff.

I might get one.

I look forward for some subjective opinions.........
Feel free to send a message to me here............
 
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With this kind of performance, it will be interesting to see what a 8,11, or 16 channel multichannel amplifier could look like, using TI Class D chips and a integrated power supply, sort of like a modern Lexicon DD8.

On the other hand 4 x 220 = $880 at which point the NC252MP seems to be a better deal at “just” 2x the price.
 
Great little amp, great that it has a trigger input so combined with a Wiim you effectively get remote controlled source select , volume and power control.
 
The measurements are OK for a TPA3255 with a PFFB implementation even if Aiyima announced better measurements on the site....
On the other hand, Aiyima sells its amp with a 48V/5A Gan power supply at the base. You need to add a few $ to get the 48V/10A one...($219)


@amirm > Aiyima confirmed that it sent you the amp with a 48V/10A Gan and 48/5A Gan PSU, can you please complete your measurements?
I think it would be appropriate for Aiyima to confirm the difference in performance with the two power supplies offered. Can you also confirm that it is really a Gan PSU ?


1709886974562.png



Now about Manufacturer specs : We don't even know with which PSU these measurements were carried out....


1709887060455.png
 
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