Aiyima A07 Max Amplifier Review

[Jacob8275]

Please play music as loud as you (or your neighbors) can tolerate while using a power meter, and then come back to publish your results. I'd be surprised if you use more than 10W per channel.

I believe @isaac507 is verifying the parameters of the power adapter alone without considering the characteristics of using it with an amplifier. Of course, a 36V 3A power adapter can instantly reach 36V 6A, but only instantly, not at a stable output power. The real 36V 6A power adapter can reach 6A stable output current, and will not be protected from power failure during the working time, its instant current can reach 9A. If the actual 36V 3A power adapter is falsely labeled as 36V 6A, it is not good.

For this kind of digital amplifier, its maximum power output depends on the maximum instantaneous power output from the power supply. I think that's why the A07 MAX with a "36V 6A" power adapter is not as powerful as the A07 with a 32V 5A power adapter.

 

[dr_mick51]

I believe @isaac507 is verifying the parameters of the power adapter alone without considering the characteristics of using it with an amplifier. Of course, a 36V 3A power adapter can instantly reach 36V 6A, but only instantly, not at a stable output power. The real 36V 6A power adapter can reach 6A stable output current, and will not be protected from power failure during the working time, its instant current can reach 9A. If the actual 36V 3A power adapter is falsely labeled as 36V 6A, it is not good.

For this kind of digital amplifier, its maximum power output depends on the maximum instantaneous power output from the power supply. I think that's why the A07 MAX with a "36V 6A" power adapter is not as powerful as the A07 with a 32V 5A power adapter.

Sure, but my point is if his maximum power consumption based in his setup (room, speakers, etc...) is por example 20w total( I'm just assuming because actual measurements had not been published). Then why people are si worried about a power supply not been able to mantain an output of more than 200W. I'm sorry but I don't understand why people believe they need all that power. Now, if you mention about peak power during cannons and explosions, then you also need to understand that why the big bulk capacitors are for. They provide a huge instant reserve of power when the power supply is not able to cope with.
The Aiyima A07 Max is an amazing amplifier, the Fosi V3 is an also amazing amplifier. People have preferences, I do. And I have both (unmodified/stock) and I prefer the way the A07 Max sounds in my particular setup (12x12 room, AK4499EX based DAC, Swans DIY3.1 with my custom "perfectionist based" crossover, 3-way DSP and Subwoofer).
Power Consumtion of only the A07 Max at idle is 6W, and while playing really loud is 10W.
Another thing I want to mention is that the opamps in all these TPA3255 and TPA3251 amps are providing gain, its not only used for inverting the signal for the differential input to chipamp. The TPA3255 has a 21dB gain (according to datasheets), but if you measure the output voltage and compare it against the input signal you see 29dB. Where is the extra 8dB coming from?. Well.. you can guess. I know many people here don't believe in opamps, I just wanted to mention that opamps are providing extra gain, and you all can make your own conclusion. And having the A07 Max 3 dB more than V3 that means the influence of opamps in V3 is less noticeable.

 

[space_duck]

This review makes me confident I will enjoy the A07 Max I have in the mail. In any other situation the possible channel imbalance would likely bother me, but that can be fixed in my AVR if necessary. The load dependency is a bigger deal, I hope it's not an issue with my speakers.
I'm curious, how hard would it be to replace the volume pot with a better one? Is that just a simple solder job?

a volume knob is such a basic and simple requirement that will fulfill much more people than the amount of people like you and those on ASR.

A simple solution to this could be a volume pot bypass switch, shouldn't add a significant cost and would please everyone.

 

[Alegretti]

Got my set today. I tested the psu and it really has a problem. The voltage drops

View attachment 330840

Of course, you've just discovered that the cable conducting the current has a resistance, use ohm's law and find out.

 

[TheBatsEar]

In any other situation the possible channel imbalance would likely bother me, but that can be fixed in my AVR if necessary.

Don't sweat it, it's likely just this tested particular potentiometer that is out of whack.

The load dependency is a bigger deal, I hope it's not an issue with my speakers.

It probably is with any speaker, but the issue is so tiny, you likely won't notice it.

I'm curious, how hard would it be to replace the volume pot with a better one? Is that just a simple solder job?

You would have to order the right part, then it's a simple job. You need desolder braid, flux, solder tin and a cheap solder iron with a good tip.
If this is your first time soldering electronics, try to get some old radio or broken device to desolder and solder back in parts. Everyone can do it.

 

[Meloman]

Многие из нас и, наконец, Амир подтвердили, что он был положительно «шокирован». с впечатлением от прослушивания его столь дорогих динамиков высокого класса. Что' еще нам нужно?
Эй, мы говорим об усилителе за 60 долларов?!!?? Айима проделал отличную работу, и я почти уверен, что проблема с дисбалансом каналов присутствует не во всех устройствах.

я talking about it/In my amplifier i dont have that problem.

 

[space_duck]

It probably is with any speaker, but the issue is so tiny, you likely won't notice it.

I've seen at least one report that a pair of speakers became unlistenable with their A07, seen no reports at all (good or bad) with the KEF Q500s I have. Hopefully they'll match just fine.

You would have to order the right part, then it's a simple job. You need desolder braid, flux, solder tin and a cheap solder iron with a good tip.
If this is your first time soldering electronics, try to get some old radio or broken device to desolder and solder back in parts. Everyone can do it.

That's good to hear. I have some soldering experience so that's an option if the pot I get is noticeable bad. How would I know which part is the correct part?

 

[frabor]

Until Aiyima addresses the issue, or we see multiple test, to find out if this is a one off error or a defective batch of pots, caution may be required and if measuring equipment is available, even basic, test the unit before it goes in production. Also, at this stage, maybe get the units from a seller with great return policies, and I am not going to name any gigantic reseller of Aiyima, and replace /sent back if the values are not satisfactory.

Well, not that I think about it, a mono test (single speaker, so do not move) with a tone with a cell phone with a dB meter app ( or REW with a measuring mic) will suffice .

 

[TheBatsEar]

speakers became unlistenable with their A07

Did they give you measurements?
Will someone be even able to hear a difference at 18 to 20kHz of +0.5dB to +1.5dB? I probably can not.

Then again, i have a treble knob to reduce treble, if it annoys me.

 

[TheBatsEar]

I've seen at least one report that a pair of speakers became unlistenable with their A07, seen no reports at all (good or bad) with the KEF Q500s I have. Hopefully they'll match just fine.

That's good to hear. I have some soldering experience so that's an option if the pot I get is noticeable bad. How would I know which part is the correct part?

I think @AIYIMA mentioned they used a Alps potentiometer. You probably can order one from Mauser or any other parts shop, if you write down the number that should be printed on it. Maybe we even have a picture where the number is visible in this thread.

If the number is gone or the part is not available, you whip out your ohm meter and measure it and order something similar. If it all fails, you bridge the contacts, attenuate upstream at the source and use it as a pure power amplifier.

 

[375HP2482]

I know many people here don't believe in opamps, I just wanted to mention that opamps are providing extra gain, and you all can make your own conclusion.

My conclusion is that, what with the NE5532 possessing far more gain-bandwidth than the Class-D stage, it can provide 8 dB of relatively noiseless gain that enables the 3255 loop to maintain its low gain of 21 dB for lower-noise operation of the power stage.

 

[K.Kevin]

I have a question for the smart people here

Background: I have some Aiyima A07 and Fosi V3’s on order to use as externals for my AVR’s surround channels. I was also going to get one A07 Max for the Center speaker, because of its bridged function. However, after this review, I put that plan on pause. I noticed it doesn’t actually provide significantly more power in “bridged mono” than when driving 2 channels, only a modest 10-20% bump. And those stereo power output measurements are also not in and of themselves much higher than what the Fosi V3 and the A07regular can already provide in stereo anyways.

Question: do you think the Fosi v3, or the A07regular would experience the same type of small bump in power output if I only drove my single center speaker from them? Even though they lack any bridged “switch”?

I know in AVR measurements, which are usually class A/B, the power output drops as you add more and more channels. I’m wondering if that same principle applies here to these Aiyima/Fosi class D’s?

 

[Guddu]

I have a question for the smart people here

Background: I have some Aiyima A07 and Fosi V3’s on order to use as externals for my AVR’s surround channels. I was also going to get one A07 Max for the Center speaker, because of its bridged function. However, after this review, I put that plan on pause. I noticed it doesn’t actually provide significantly more power in “bridged mono” than when driving 2 channels, only a modest 10-20% bump. And those stereo power output measurements are also not in and of themselves much higher than what the Fosi V3 and the A07regular can already provide in stereo anyways.

Question: do you think the Fosi v3, or the A07regular would experience the same type of small bump in power output if I only drove my single center speaker from them? Even though they lack any bridged “switch”?

I know in AVR measurements, which are usually class A/B, the power output drops as you add more and more channels. I’m wondering if that same principle applies here to these Aiyima/Fosi class D’s?

Post in thread 'Fosi Audio V3 Amplifier Review'
https://audiosciencereview.com/foru...-audio-v3-amplifier-review.45757/post-1798566

 

[Guddu]

Post in thread 'Fosi Audio V3 Amplifier Review'
https://audiosciencereview.com/foru...-audio-v3-amplifier-review.45757/post-1798566

Here is an example:
Just found this amazing item on AliExpress. Check it out! $43.99 28％ Off | AIYIMA 600W Power Amplifier TPA3255 Sound Amplifier Class D Mono Amplify Speaker Digital Amplifcador Home Audio Amp

https://a.aliexpress.com/_m0CrtWy

Don’t know how much would you be able to save but you can have a look and compare.
I wanted to keep Aiyima stuff to Aiyima’s thread, so posted the link here.

 

[K.Kevin]

Here is an example:
Just found this amazing item on AliExpress. Check it out! $43.99 28％ Off | AIYIMA 600W Power Amplifier TPA3255 Sound Amplifier Class D Mono Amplify Speaker Digital Amplifcador Home Audio Amp

https://a.aliexpress.com/_m0CrtWy

Don’t know how much would you be able to save but you can have a look and compare.
I wanted to keep Aiyima stuff to Aiyima’s thread, so posted the link here.

I noticed these are marketed like a subwoofer amp. Do you know if they will be good enough for the entire frequency band up to 20khz?

I do like this as an option, although the lack of ASR reviews makes it hard to trust. My V3’s and A07’s sound very high fidelity, and getting a V3 for my center speaker won’t cost that much more than these AliExpress ones.

 

[Guddu]

I noticed these are marketed like a subwoofer amp. Do you know if they will be good enough for the entire frequency band up to 20khz?

I do like this as an option, although the lack of ASR reviews makes it hard to trust. My V3’s and A07’s sound very high fidelity, and getting a V3 for my center speaker won’t cost that much more than these AliExpress ones.

It’s just a mono amplifier, doesn’t really have any low or high pass filters etc. So frequency response has no difference than any other amplifier.
If there isn’t any cost benefit then probably stick to one of those amps which you trust.

 

[ninetylol]

I noticed these are marketed like a subwoofer amp. Do you know if they will be good enough for the entire frequency band up to 20khz?

I do like this as an option, although the lack of ASR reviews makes it hard to trust. My V3’s and A07’s sound very high fidelity, and getting a V3 for my center speaker won’t cost that much more than these AliExpress ones.

You got both measurements for fosi and a07max, two full threads of opinions and prices in your area. What are you even asking?

 

[K.Kevin]

You got both measurements for fosi and a07max, two full threads of opinions and prices in your area. What are you even asking?

Basically asking if an A07/Fosiv3 type amp would provide more power if only using a single channel, similar to how AVR’s provide more power when only one-channel driven specs used. This was my question for context:

“I noticed it [the A07 Max] doesn’t actually provide significantly more power in “bridged mono” than when driving 2 channels, only a modest 10-20% bump. And those stereo power output measurements are also not in and of themselves much higher than what the Fosi V3 and the A07regular can already provide in stereo anyways.

Question: do you think the Fosi v3, or the A07regular would experience the same type of small bump in power output if I only drove my single center speaker from them? Even though they lack any bridged “switch”?

I know in AVR measurements, which are usually class A/B, the power output drops as you add more and more channels. I’m wondering if that same principle applies here to these Aiyima/Fosi class D’s?”

 

[ninetylol]

@Gygess you got Power numbers in both measurements. You prolly wont get more with the Fosi without a mono switch even if you only drive one channel (others correct me, if im wrong).

Also remember that you only get a 32v Power supply with fosi V3 at most dealers, while aiyima got 36v6a as standard.

 

[K.Kevin]

@Gygess you got Power numbers in both measurements. You prolly wont get more with the Fosi without a mono switch even if you only drive channel (others correct me,if im wrong).

Also remember that you only get a 32v Power supply with fosi V3 at most dealers, while aiyima got 36v6a as standard.

Well, no, technically I don’t: Amir’s reviews don’t measure one channel output. The only time I’ve ever seen that is in some of his AVR reviews (obviously excluding monoblock reviews)

If I had those measurements for one channel driven specs for the amps I’m talking about I wouldn’t be asking my question

I still appreciate your opinion though, so now it’s 1:1, one person saying there will be a minor bump even without the mono switch just powering one channel, and you saying there won’t be.

Good point on the power supplies, but I have a 48v5a V3 already. If I could measure the power output myself to determine the answer one and for all I would, but I’m not that tech savvy.