AIYIMA A70 Stereo Amplifier Review

[john61ct]

Damping factor and output impedance are obviously related. However, pretty much any modern solid state amplifier has more than sufficient damping factor.

THIS

So long as an amp damping factor gets above 20, further increases yield zero audible changes to bass tightness or frequency response deviation.

Maybe 50 if you're fussy.

Looking for higher is a waste of time, at those levels electrical braking is dependent solely on the cabling guage and the speakers' components

 

[Space is the place]

I ended up with a couple of A70s, got them to power some Dali Picos speakers that i have at work with a Sunfire sub, they are a bit compromised (partly because the room is massive), but work well and get to a surprising volume. I've also tried them at home with a few different speakers, they didn't really work well with a pair of ProAcs i have.
Out of curiosity i tried both A70s actively bi-amped into some NHT evolutions. I've not used these speakers for a few years so forgot what they're capable of! One A70 for the main monitors and the other A70 for the dual subs, both amps both running from the NHT X1 crossover, all fronted by a Topping DX5II as the preamp/Dac, tbh i didnt give them much hope of working in this setup, however the opposite was the case, they're hilariously good! Providing really life like dynamics and volume, while still staying clean and composed, very impressed!

 

[dcolak]

THIS

So long as an amp damping factor gets above 20, further increases yield zero audible changes to bass tightness or frequency response deviation.

Maybe 50 if you're fussy.

Looking for higher is a waste of time, at those levels electrical braking is dependent solely on the cabling guage and the speakers' components

Benchmark engineers think differently.

 

[NTK]

Benchmark engineers think differently.

The Benchmark folks fudged a few things.

First, they calculated the damping factor using nominal impedance (8 Ω) and calculate deviations using a minimum and maximum impedance of 2.6 Ω and 18 Ω. It might have happened somewhere, but it is an exceeding poor and questionable practice to rate you speaker at 8 Ω nominal when it has a minimum impedance of 2.6 Ω.

Second, they used a significantly more stringent criteria of ≤0.2 dB deviation. The usually recommended damping factor of 20 (resulted deviation about ≤1 dB) is based on practicality. Look at the frequency response of any passive loudspeaker (since we are talking speaker amplifiers here). How many of them have a frequency response consistently flat to 1 dB? People may be able to discern a FR deviation of 1 dB in rapid switching AB type testing. But in real life usage when FR adaptation is completely normal and natural?

 

[mlsstl]

Benchmark engineers think differently.

The question is how much input their marketing department has on what gets published in their advertising and manuals. As just noted, there are a lot of games that can be played while still remaining technically correct.

 

[john61ct]

Benchmark engineers think differently.

Just to double-check, you mean those employed by a particular company?

As opposed to a niche job / specialised profession classification?

@dr toole for example, if not Amir and Erin...

PS Is Floyd Toole no longer active here?

 

[Bruce Morgen]

PS Is Floyd Toole no longer active here?

I don't know what passes for "active", but he does comment on ASR threads from time to time.

 

[NTK]

I don't know what passes for "active", but he does comment on ASR threads from time to time.

Dr Toole is active here, despite being harassed by bennybbbx. This is his most recent (yesterday) post.

Floyd Toole's Toronto AES presentation from October 28, 2025

I commented at some length earlier in this forum (which thread?) on this topic, and it is discussed in my book. Putting it succinctly, all the indicators in Sean's model pointed to a flat and smooth direct sound with smooth spatially averaged curves (listening window, early reflections, PIR and...

www.audiosciencereview.com

 

[Wooferhead]

Is it better to get a pair of A20 Mono or one A20 Stereo or A70 Stereo?

 

[john61ct]

Likely no audible difference unless your room / distance is large and your speakers thirsty AND you want to squeeze every last dB of SPL

 

[ModDIY]

Hi,
from Canada, the 48V 10A SMPS GAN is $50 more expensive than the 5A version, double the price.

I don't think I'll spend more for 10A, especially since the device will overheat at very high volume.

What do you think?

 

[john61ct]

In fact on many platforms the 5A PSU vs none is just $15-20 difference

while quality 10A PSUs go for $70+

My take is if you think you "need" every last Watt / ampere of output for big room / thirsty speakers,

might as well go for adjustable PSU so you can go to 10A at 51V on amps / boards that allow it when hosting film night / dance parties

and scale back to ~40V for longevity in normal usage

 

[Dave TR3A]

Hi,
from Canada, the 48V 10A SMPS GAN is $50 more expensive than the 5A version, double the price.

I don't think I'll spend more for 10A, especially since the device will overheat at very high volume.

What do you think?

Whether the extra current will be beneficial will depend on your speakers (ohms & efficiency), your typical listening volume, and how far your MLP is from the speakers. With that information it’s possible to calculate what your speakers will draw.

In general, unless the speakers present a very low load (e.g., 2 ohms) the extra current will not be needed.

You seem confident that the amp will overheat. Why? None of my Aiyima amps run hot.

 

[ModDIY]

Whether the extra current will be beneficial will depend on your speakers (ohms & efficiency), your typical listening volume, and how far your MLP is from the speakers. With that information it’s possible to calculate what your speakers will draw.

In general, unless the speakers present a very low load (e.g., 2 ohms) the extra current will not be needed.

You seem confident that the amp will overheat. Why? None of my Aiyima amps run hot.

Regarding the heat, I'm not sure. I know it's an issue with the Douk A5, and I thought that even though the A70's chassis is larger, it might still get hot at 10A.

Anyway, the room isn't very big, let's say average size, and I only listen at moderate volume occasionally. Not for parties.

My speakers have an impedance of 8 ohms and a minimum of 3.7 ohms, an efficiency of 88dB, and a maximum power of 125W. I think that knowing this, 48V 5A is more than enough.

In addition to the Sabaj A30a, I have the 2019 A20a with dual Infineon MA12070, delivering 35W at 8 ohms and 60W at 4 ohms, and I have plenty of power.

My friend bought the A70 and 48V 5A GAN; I was able to test it at home and the power is very satisfactory.

 

[Laserjock]

Always get the best you can and you won’t have
To wonder

 

[Dave TR3A]

Regarding the heat, I'm not sure. I know it's an issue with the Douk A5, and I thought that even though the A70's chassis is larger, it might still get hot at 10A.

Anyway, the room isn't very big, let's say average size, and I only listen at moderate volume occasionally. Not for parties.

My speakers have an impedance of 8 ohms and a minimum of 3.7 ohms, an efficiency of 88dB, and a maximum power of 125W. I think that knowing this, 48V 5A is more than enough.

In addition to the Sabaj A30a, I have the 2019 A20a with dual Infineon MA12070, delivering 35W at 8 ohms and 60W at 4 ohms, and I have plenty of power.

My friend bought the A70 and 48V 5A GAN; I was able to test it at home and the power is very satisfactory.

Well, since you've already tried it and found it satisfactory, it sounds like you have your answer.

By my calculations, at 125W (i.e., the limit of what your speakers can handle) your speakers would deliver about 100 dB SPL at a listening position 3m from the speakers. At that volume, you could start to incur hearing damage after about 15 minutes. To reach that SPL, the output to the 8 ohm speakers would have to be 31.75 Vrms and the current drawn would be just under 4 amps. The 5A power supply ought to be just fine.

If your speakers were nominally 4 ohm (instead of 8 ohm) then at 125W the amp would have to output 22.5 Vrms and the speakers would draw 5.6 amps.

 

[john61ct]

Yes the 5A PSU will serve just fine.

Note that even with a 100A supply, that is just an "offered" maximum, your amp will not draw any more current until the volume control and speaker demand cause it to PULL more current

so "overheating" however you define that does not happen because of higher ampere capacity

it can be prevented by keeping Watts low by abstaining from turning Volume up too high, and keeping Voltage lower than maximum tolerated by the amp

 

[mlsstl]

Note that even with a 100A supply, that is just an "offered" maximum, your amp will not draw any more current until the volume control and speaker demand cause it to PULL more current...

A good example of this is a 15 amp wall outlet in your house. It is capable of supplying about 1,800 watts of power. But, plug in your bedside alarm clock and the outlet supplies only 5 or 10 watts -- exactly the amount needed to run the clock and its display. The other 1,790 watts go unused (until you plug something else in). It is the requirements of the appliance that you plug in that determines how much power is provided. With an audio amplifier, the power requirements constantly vary with the music and how loudly it is being played.

 

[magreen]

A good example of this is a 15 amp wall outlet in your house. It is capable of supplying about 1,800 watts of power. But, plug in your bedside alarm clock and the outlet supplies only 5 or 10 watts -- exactly the amount needed to run the clock and its display. The other 1,790 watts go unused (until you plug something else in). It is the requirements of the appliance that you plug in that determines how much power is provided. With an audio amplifier, the power requirements constantly vary with the music and how loudly it is being played.

Speak for yourself. I have a Class A alarm clock that draws a continuous 250 watts at all times except when it's ringing. Its alarm sounds like pure audio nirvana. Such sharp transients and slam. And pitch black silent background when it's not ringing. Keeps me nice and toasty.