Aiyima A07 Max Amplifier Review

[wwenze]

I have doubts about its longevity.

Hmm... As an owner of multiple such ebay amps I have no doubts about the amps' longevity. Of course the usual caveat of "a bad product still lasts long for 90% of owners" applies.

Plus it's usually the power adapter that gives out first, without exception.

 

[Guddu]

I may be wrong but if it will ever achieve a steady 600 watt at 2 Ohm for more that 30 sec with this case it's color may turn to hot glowing red instead of black/blue.

Thanks Amir!

I am not looking at 600 watts at all, and any one following ASR would know it as well.

 

[wwenze]

those numbers are always with 10% THD which is useless in practice.

I can imagine the "crest factor" people coming in

"errrrr but ackually, most of the music signal is 10 to 20dB below the peak, so most of the time you will be having the nice 0.01% THD @ 40W, and only occasionally getting 10% THD @ 80W"

 

[uwotm8]

Ez POOR due to imbalance

 

[mlieber507]

This is a review and detailed measurements of the Aiyima A07 Max stereo class D amplifier. It was sent to me by the company and sells for (I think) $85 with the included power supply:
View attachment 329649
I like the little design touches and the much heavier enclosure (made out of steel?). I really appreciate the larger and staggered speaker binding terminals:

View attachment 329650
As you see, the power supply is rated at 36 volts @ 6 amps. It has no branding though so not sure about the safety marks. There are vent holes underneath and during the testing, the case stayed quite cool.

Let's see how it measures.

Aiyima A07 Max Measurements
As usual we start with our dashboard:
View attachment 329651
I had a hard time setting the output to 5 watts due to fairly large channel mismatch. I did feed each channel independent (not shown) to get them both at 5 watts and results were similar. As is, performance is very good:
View attachment 329652
Zooming in:
View attachment 329653

Noise performance is good:
View attachment 329654
Multitone shows increasing distortion at high frequencies (fairly typical):
View attachment 329656

Which winds up hurting 19+20 kHz more:
View attachment 329657

Frequency response shows the class load dependency in budget class D amplifiers but also the channel balance issue:
View attachment 329658

Crosstalk is pretty good:
View attachment 329659

Let's see how much power we have:
View attachment 329661
View attachment 329662
View attachment 329663

Pretty good amount but one channel shows that rising distortion above a few watts which we also saw in the dashboard.

There is some frequency dependency as we would expect in this class of amplification:
View attachment 329664

Amplifier is stable on power up:
View attachment 329655

The volume control is also the on/off switch. So I can't test the on/off pop the usual way as that would be at minimum level compared to other amps with separate power switch that are at full gain. So while not practical, I turned the amp on/off using the AC plug:
View attachment 329666

Conclusions
Aiyima has made good strides in the mechanical and outside design of the amplifier with heavier chassis with venting. The look is simpler and cleaner. And bind posts are now quite proper. Electrically, performance is similar to their other offerings which is to say it is very good. The only thing I didn't like here compared to others I have tested is channel imbalance. This is strange as I had the volume control fairly up high (as you see in the review picture) so not at the lower levels where channel imbalance usually comes up. This would cause the stereo image to shift to one side some. The sample you get may be the same, worse or better. At this price, I guess we can't expect hand picked pots but I was hoping for better.

For above reasons, the Aiyima A07 Max is not something I would buy. But your conclusion may be different.

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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/

This amplifier probably should be tested at 48 volts.10 amps. Its performance is highly dependent on power supply voltage and current. Further, the amp can be purchased from Aliexpress with no power supply for $50.00 and an extra $38.00 to Amazon for a 500 or 600 watt 48 volt supply. Also, it would be nice to have a review of the amp's mono operation. One could run 2 mono amps from the 48 volt 10 amp Amazon SMPS.

 

[Toni Mas]

Strange that a similar amp made with the same power chip TPA3255 and opamps by Fosi have shown quite better measurements. I would have considered clones and bet both share same schematic suggested by the chip manufacturer ...

Imho the power specs are totally over optimistic... Peak power based on psu voltaje rails?

 

[Ajax]

Hi Amir,

Any chance of hooking this amp up to your revel speakers? I'm intrigued if the SPL it can produced before noticeably distorting is sufficient for a second or third system. i.e. can it play loud enough to fill a bedroom or small office?

I know it is all very subjective but when I started out in this hobby in 1978 my first "real" amplifier was a Sansui AU317, which was revered and I personally thought was wonderful. It's specs are very similar to the A07 and cost then about $200, being $950 today according to Google, i.e. over 10 times the price of the A07.

MANUFACTURER'S SPECS FOR AU317
Power output: 50 watts per channel into 8Ω (stereo)
Frequency response: 5Hz to 70kHz
Total harmonic distortion: 0.03%
Damping factor: 70
Input sensitivity: 20mV (mic), 2.5mV (MM), 150mV (line)
Signal to noise ratio: 77dB (MM), 100dB (line)
Channel separation: 65dB (MM), 73dB (line)
Output: 150mV (line), 1V (Pre out)
Speaker load impedance: 8Ω (minimum)

In fairness the Sansui has a lot more features but I would be interested to know, from a pure performance and sound reproduction view point, if the cost of budget amplifiers has reduced over time as much as the top end.

e.g. the excellent Apollon NCx500ST, which produces 245 watts of clean power and received a 90% rating from ASR members, is only $1,170, compared to many celebrated brands such as Krell, McIntosh, Music Fidelity etc that cost at least 10 times that, some 20 times.

 

[Lambda]

Which winds up hurting 19+20 kHz more:

Thanks for now including this high frequency IMD test.
It’s veery reveling for Class D amps that look otherwise fine.

I still think this Amp is ok and usable.
Would be nice to See bridged mono performance

 

[Lambda]

The original and the sample I have had 50 volt caps. Due to you all beating them up , they made a running change to 63 volt.

which has now been updated to 63v capacitors.

I suppose 63V caps will have Lower Capacity and ESR.
So they kind of send out "golden sames" with better performance (at least from the capacitors how this influences the total performance is unclear ) but lower longevity.

 

[Drengur]

If you have time (which I think you don't), a test in mono would be very interesting as I think that is where this amplifier has a defining use case compared to some other similar products.

 

[TonyJZX]

am i thinking that because these amps use their own custom vol. knobs and not commodity items like the pga2310 njw1194 then this sort of part variation is typically what you get?

 

[OldTimer]

This appears to be a different design to the prior A07 models;

View attachment 329676

It just goes to show that independent measurements are needed, without assuming prior performance means future performance in all aspects. Thanks for the testing results.


JSmith

Components inside is better than Fosi Audio V3 but why the measurement is not better?

 

[Toni Mas]

Components inside is better than Fosi Audio V3 but why the measurement is not better?

Amir also measured the cheaper AIYIMA A07 Pro in may with a similar design TPA3255 based too and measurements were better too.

Btw all these miniamps claiming those 300w are built around this chip TPA3255. Main differences are about mono stereo or bridgeable, and the specs of the separated PSU, though some models come with an internal one.

 

[TonyJZX]

i dont think components matters that much to SQ?

reliability? yes

i think both the V3 and Max use high quality brand name components... that's not an issue to me

otherwise at this point it looks like the ZA3 balanced is the king? with xlr thrown in

 

[AltoVariago]

when an amp has such a difference between the channels SINAD and other measurements are irrelevant. BIG NO.

 

[Lambda]

i dont think components matters that much to SQ?

Inductors in a Class D matter a lot.
There are big differences in Linearity.

https://www.ti.com/lit/an/sloa242a/sloa242a.pdf?ts=1701109982915&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTAS6584-Q1

And they are the most expensive part in the Amp...

at this point it looks like the ZA3 balanced is the king? with xlr thrown in

XLR is dose not mean it will be better or that it’s having any benefits with noise suppression.
It might as well have have a passive adapter and and is not using the inverted input at all.

 

[Toni Mas]

Xlr for a couple of feets of interconects?

 

[Joe Smith]

Aiyima staff, if you are continuing to watch this review thread, can you comment on the channel imbalance issue? Do you think that the unit Amir received could have had a flawed volume pot and that therefore his measurements are for a "defective" unit?

 

[GiBo61]

Aiyima staff, if you are continuing to watch this review thread, can you comment on the channel imbalance issue? Do you think that the unit Amir received could have had a flawed volume pot and that therefore his measurements are for a "defective" unit?

Not very wise of Aiyima to send a product to be reviewed without having tested it first...

 

[Toni Mas]

Not very wise of Aiyima to send a product to be reviewed without having tested it first...

Typical chinese QC... Why bother?