Aiyima A07 Max Amplifier Review

[Lambda]

Can anyone explain the higher noise with the 48v PSU? At the risk of saying something silly: Is the gain different?

The Output stage of the Class D chip is switched on or of so with higher voltage it has more "Gain"
This is Compensate by Shorter on time of the output switch.

Since the switching time in a class d is the analog part it has some noise and if time gets shorter the noises gets more significant compared to the on time.

Also the output inductor (and caps) get more ripple this makes them more "noisy" and more non linear

 

[amirm]

Listening tests added to the review:

"
AIYIMA A07 Max Listening Tests
I connected the A07 Max, don't laugh, to my $23,000 Revel Salon 2 speakers as requested by a member. I must say, I was not remotely prepared for what I heard. This little amp with its 36 volt/6amp power supply had no trouble driving the Revels to incredible dynamics! Resolution and detail was superb. Deep, sub-bass was produced with no sign of amp straining or wanting to turn off. I am still listening to it as I type this and can't believe what I am hearing. The binding posts on the speakers probably weigh as much as this amp!

Granted, I am scared of turning it up to max volume as to risk damaging my speakers should something go wrong. But so far, even at very elevated listening levels, the amp is performing beautifully. It defies one's or at least my intuition. Feed this amp well recorded music and pair it with great speakers and you are set.

Note that if you have less sensitive speakers, you may run out of power."

 

[Guddu]

Listening tests added to the review:

"
AIYIMA A07 Max Listening Tests
I connected the A07 Max, don't laugh, to my $23,000 Revel Salon 2 speakers as requested by a member. I must say, I was not remotely prepared for what I heard. This little amp with its 36 volt/6amp power supply had no trouble driving the Revels to incredible dynamics! Resolution and detail was superb. Deep, sub-bass was produced with no sign of amp straining or wanting to turn off. I am still listening to it as I type this and can't believe what I am hearing. The binding posts on the speakers probably weigh as much as this amp!

Granted, I am scared of turning it up to max volume as to risk damaging my speakers should something go wrong. But so far, even at very elevated listening levels, the amp is performing beautifully. It defies one's or at least my intuition. Feed this amp well recorded music and pair it with great speakers and you are set.

Note that if you have less sensitive speakers, you may run out of power."

The reason for me to wait for ASR measurement and review so eagerly was similar expression as yours when I hooked it up to my setup.
It sounds so good and neutral.
I am glad you decided for listening test, don’t think you have done the same with other cheap amplifiers (or may be I missed it in reviews).

 

[SorenTyson]

I think Amir does a great job providing us with all the facts and had this information been around 30 years ago I would have saved a fortune.

We all have different budgets and preferences. We can then apply the insights from Amir to our purposes.

This is a cheap amp and it has a shortcoming of a 1 db channel level difference. That’s good knowledge, then for each of us to decide whether we want to buy this or something more expensive with matching levels.

Thank you Amir

 

[Overseas]

Previous products from Aiyima were pretty good without any fails. So i do hope Aiyima is so transparent, that they 1. Send samples in for free for measurements and 2. They dont seem to cherry pick their samples.

I understand your thoughts, but I think you gotta give credit where credit is due.

You mean they genuinely do bad products without knowing it.

 

[Joe Smith]

You mean they genuinely do bad products without knowing it.

I think looking at this review and the amp overall, calling it a "bad product" because they have some slight variation in their volume pots is pretty harsh. They are using a parts mix to arrive at the cost per unit they think is right. Both this amp and the Fosi V3 give a lot of value for the money, particularly for those of us on a tighter budget for equipment.

Big thanks to @amirm for checking the 36v power brick, that sets my mind at ease that it can provide 6 amps current.

 

[Guddu]

You mean they genuinely do bad products without knowing it.

I have 4 Aiyima amps now, and haven't had any issues or failures.

I have no way to be sure, but this channel imbalance might just be a random unit issue rather than design issue with all A07 amps.

 

[Jacob8275]

OK, for the third time I unpacked this amp to measure its power supply. Review is updated. Here is a shot at 6amp draw:

Thank you @amirm for your test. May I ask, when the current reaches 6A, is the voltage dropping continuously or fixed at 34.8V?
Besides, after the voltage and current are fixed, it needs to keep working at this power for a period of time, about 15 to 45 minutes, and if it doesn't cut off, means it meets the standard. If it works continuously for a while and then cuts off , it only means that its instantaneous current can reach 6A, but the continuous working current can not reach 6A.

For the voltage and current specified on the power supply, this represents its rated continuous output power, not instantaneous. If the rated current is 6A, the instantaneous current might reach 10A, but it cannot sustain operation continuously at 10A; it's only for momentary operation. Therefore, it's important for us to understand what the actual continuous output power of this power supply is.

 

[TonyJZX]

re: A07max driving $20,000+ speakers

even with the balance and the lack of SOTA the reality is performance is more than acceptable to the OP so what is one to make of this?

is the speaker flattering to the amp?

 

[375HP2482]

This again is far more power than the stock 36 volt

Not much difference in total power. The stock 36V supply tops out at 2 ohms, versus 4 ohms with the 48V supply -- both over 200 watts.

I noticed one SINAD improvement since my OG A07: the power line artifacts are gone.

 

[amirm]

Thank you @amirm for your test. May I ask, when the current reaches 6A, is the voltage dropping continuously or fixed at 34.8V?
Besides, after the voltage and current are fixed, it needs to keep working at this power for a period of time, about 15 to 45 minutes, and if it doesn't cut off, means it meets the standard. If it works continuously for a while and then cuts off , it only means that its instantaneous current can reach 6A, but the continuous working current can not reach 6A.

I left it on with 6 amp draw for 2 to 3 minutes and it survived without even getting warm. So I think it is fine. Music is not going to demand continues power for 45 minutes.

 

[pl4w]

Great review and measurements as usual.

Too bad that wasn't a 48V-powered / 63V caps version that was tested.

 

[TheBatsEar]

I just read a review at Amazon that said sound better with Muses02 than with Sparkos

I would say the device is a plain Fosi V3 copy, shouldn't different OPAmps measure more or less the same?

What is an acceptable way of calling this particular class of equipment?

It's hifi from China.
You don't call Focal speakers Baguette-Fi or Elac speaker Kraut-Fi either.

even with the balance and the lack of SOTA the reality is performance is more than acceptable to the OP so what is one to make of this?

That most differences we perceive are in our head.
If random music has less than 40dB of dynamics, an amp with artifacts below -80dB is transparent.
I'm sure @amirm has some high dynamic tunes in there, but more than 80dB is unlikely.
I measure 40 to 50dB room noise, so we are talking about 120 to 130dB peak with 80dB dynamic.
For all intents and purposes, this amp is transparent to most. And it has more than 30 or so clean watts, so it has plenty of power for most too.

 

[NoMoFoNo]

Listening tests added to the review:

"
AIYIMA A07 Max Listening Tests
I connected the A07 Max, don't laugh, to my $23,000 Revel Salon 2 speakers as requested by a member. I must say, I was not remotely prepared for what I heard. This little amp with its 36 volt/6amp power supply had no trouble driving the Revels to incredible dynamics! Resolution and detail was superb. Deep, sub-bass was produced with no sign of amp straining or wanting to turn off. I am still listening to it as I type this and can't believe what I am hearing. The binding posts on the speakers probably weigh as much as this amp!

Granted, I am scared of turning it up to max volume as to risk damaging my speakers should something go wrong. But so far, even at very elevated listening levels, the amp is performing beautifully. It defies one's or at least my intuition. Feed this amp well recorded music and pair it with great speakers and you are set.

Note that if you have less sensitive speakers, you may run out of power."

This is how I felt when I swapped the Fosi V3 into my main system. I could not believe how well it performed. $105USD with 48V power supply and it sounded every bit as good as any 'proper' 'big iron' amp I've had in the system. I've concluded that never again will I seek out expensive amplification but rather look for gems like these at wildly reasonable prices. Even Hypex and Purifi seem like overkill to me at this point. I know they perform better but they also cost at least 5X something like the V3 or A07 Max. If I cannot hear the difference I'll happily remain in this value lane.

 

[ninetylol]

FYI my aliexpress A07 Max ordered on the 15th November got 63V caps already.

65€ with included 48V5A supply is money well spent Id say!

 

[TheBatsEar]

FYI my aliexpress A07 Max ordered on the 15th November got 63V caps already.

65€ with included 48V5A supply is money well spent Id say!

Damn, that sounds like a very good price, mate. Should have gotten two, just to have double the power.

 

[ninetylol]

Damn, that sounds like a very good price, mate. Should have gotten two, just to have double the power.

I actually did, but not sure i want to take the hassle with monoblock volume control

 

[TheBatsEar]

This is how I felt when I swapped the Fosi V3 into my main system.

What did it replace?

 

[TheBatsEar]

I actually did, but not sure i want to take the hassle with monoblock volume control

I have a preamp (MiniDSP Flex), so i would attenuate there.

If you don't have a preamp you should get one! You have an excuse now!

 

[ninetylol]

I have a preamp (MiniDSP Flex), so i would attenuate there.

If you don't have a preamp you should get one! You have an excuse now!

I have a WiiM, but still you need to balance the two monoblocks with a multimeter first. And i dont need the extra power, it would just be a gimmick Maybe I will use one amp for a DIY sub project.