Aiyima A07 Max Amplifier Review

[HarmonicTHD]

i cannot comment on your setup, as i have no experience there.

but, regarding expensive amps/speakers; did you see the video where the designer of cube audio and qualio speakers says the fosi za3 (and the aiyima a07) are better driving his qualio iq speakers (€6,900.00), than the €4,500.00 naim integrated amp that he was using previously? in comparing the fosi za3 to the aiyima a07, he says the aiyima is a bit more open and dynamic, while the fosi has more "richness". and he mentions a uk buddy who prefers the aiyima a07 max amp to a €10,00.00+/- vitus audio integrated amp. he did not say which speakers he was using. (i suspect the cost is higher, as the least expensive integrated amp i see on the vitus website is €17,000.)

and, both per the youtube vid, and ungeduld's comments above, there may be slight differences between amps, and between amp/speaker synergy...

doug s.

Sorry to say. These videos are useless. Just anecdotes and fairy tales and infomercials at best without evidences when it comes to sound. One can not compare audio gear sighted without matching levels with any reliability. This is as far from science as it gets.

(Watch the video from Amir on Blind testing and Amp testing to learn how it is done correctly).

 

[HarmonicTHD]

Explored some more and found that pros/cons come down to class A/AB vs class D amps. Class D amps are supposed to be highly efficient, small and economical but are not supposed to be good in sound fidelity.Seems as per video shared above, these amps are good in SF also! If so, it may revolutionize the amps industry?!
BYW, thanks for sharing that video!

This is nonsense and an audiophile myth - class has nothing to do with sound. It’s the engineering that counts. There are great class AB (eg Benchmark AHB2) and great class D (eg NC or Hypex etc based amps reviewed here) and of course badly engineered ones of each class. Both can be identified by Amir’s reviews.


As for your audio chain:
The Topping in there is strange. Are you sure you are not overdriving the input of the Aiyma? (The Aiyma with its ca 29dB gain will easily be driven by the usual preout signal of around 1V or more).

In your case however, either use the AVR only, as it has some 160w into 4ohms, and as the Aiyma is not adding anything/much here anyway (plus it has that strange FR response). Also there is a good chance that you drive that relative weak Aiyma into clipping and damaging your speakers (tweeters).

Or alternatively spend some money and get some much more powerful power amps eg the above mentioned Hypex or NC based amps from one of the various vendors. But check that you get the versions with the correct gain (around 26dB I would guess without looking into details) matching your AVRs pre out voltage.

 

[Vijay_kumar74]

Please review this thread

Class D FAQ

This topic is dedicated to Frequently Asked Questions about class D amplifiers. If you have been directed here the reason is that it is easier to concentrate the frequent answers here instead of repeating them in several topics. Q1: Class D power ratings cannot be true. How can these small and...

www.audiosciencereview.com

Quite interesting thread! Thanks for sharing!

 

[HarmonicTHD]

Quite interesting thread! Thanks for sharing!

Just an example of a powerful and very very low noise / distortion class D amp (as mentioned above):
Thread 'Audiophonics HPA-S400ET Review (Stereo Amplifier)'
https://audiosciencereview.com/foru...ics-hpa-s400et-review-stereo-amplifier.32014/




And a similar class AB example:
Thread 'Benchmark AHB2 Review (Updated Measurements)'
https://audiosciencereview.com/foru...hmark-ahb2-review-updated-measurements.50844/

 

[Vijay_kumar74]

This is nonsense and an audiophile myth - class has nothing to do with sound. It’s the engineering that counts. There are great class AB (eg Benchmark AHB2) and great class D (eg NC or Hypex etc based amps reviewed here) and of course badly engineered ones of each class. Both can be identified by Amir’s reviews.


As for your audio chain:
The Topping in there is strange. Are you sure you are not overdriving the input of the Aiyma? (The Aiyma with its ca 29dB gain will easily be driven by the usual preout signal of around 1V or more).

In your case however, either use the AVR only, as it has some 160w into 4ohms, and as the Aiyma is not adding anything/much here anyway (plus it has that strange FR response). Also there is a good chance that you drive that relative weak Aiyma into clipping and damaging your speakers (tweeters).

Or alternatively spend some money and get some much more powerful power amps eg the above mentioned Hypex or NC based amps from one of the various vendors. But check that you get the versions with the correct gain (around 26dB I would guess without looking into details) matching your AVRs pre out voltage.

Tried again but without Topping, the audio was very feebly audible. With Topping it became much better. However changed the setup back to speakers directly connected to AVR. This way it sounds much better.
However, will explore other compatible amps.

 

[HarmonicTHD]

Tried again but without Topping, the audio was very feebly audible. With Topping it became much better. However changed the setup back to speakers directly connected to AVR. This way it sounds much better.
However, will explore other compatible amps.

Topping btw AVR and Ayima:
Yes unless someone can analyze the exact values keep the Topping out as there is a big chance you damage your speakers by clipping the Ayima.
The Aiyma has ca 50W into 8 ohm (actually only 40, but with 50 I can do the math in my head. And btw your AVR has more so it doesn’t make sense of using the Ayima in the first place). 50W results into 20V output voltage into the speaker. Now take the ca 26dB gain (factor 20) and you land at 1V input voltage to clip the Ayima. Your AVR preouts can easily do that normally. Now if you put the Topping in between and if that happens to add even more gain (I didn’t look into the details but you say it sounds louder), this can easily clip the Ayima and damage your tweeters.

HT Application:
To give you some numbers/facts (not YT anecdotes) why the Ayima is a risk for HT and your speakers even if you keep it directly attached to the AVR preouts.
Assuming your speakers have a sensitivity of around 87dB/W. At 9ft listening distance it takes ca 50W already to get to peaks of ca 96dB SPL and that’s assuming that you listen on average to ca 76dB SPL (remember THX is 85dB average). So those 96dB get the Ayima already to clip. Now what happens if your speaker drops to 4 or even 3 ohms. That more than doubles your power requirement and you are looking at ca 130W or even 266W if that one time you listen extra loud and have peaks of 105dB SPL. Each scenario will more than clip the Ayima, send high energy at high frequencies plus aided by the weird peak in FR response will have a very good chance to overheat and burn out the tweeter of your 4k speaker. Not worth the 90bucks of the Ayima.

The Ayima is a great amp for low/mid level close listening eg an office but not for your application of Home Theater. Again I didn’t look up all the exact numbers but I think the big picture is correct.

 

[doug s.]

Sorry to say. These videos are useless. Just anecdotes and fairy tales and infomercials at best without evidences when it comes to sound. One can not compare audio gear sighted without matching levels with any reliability. This is as far from science as it gets.

(Watch the video from Amir on Blind testing and Amp testing to learn how it is done correctly).

sorry to say, this video is far from useless. in this case, you don't even have to listen to the music, which i agree is useless. there's no way you can hear the differences, even if it's well recorded and you're using hi-end headphones.

but this video is done by a designer of very well respected hi end speakers. and he's not selling amps. there's a reason he switched to these amps to demo his speakers at hi end audio shows; he wants to sell his speakers, not cheap amps from another mfr. you can literally throw these amps away if you don't like them, and you will still be losing less money than by purchasing a new "hi end" amp and re-selling it...

doug s.

 

[doug s.]

Topping btw AVR and Ayima:
Yes unless someone can analyze the exact values keep the Topping out as there is a big chance you damage your speakers by clipping the Ayima.
The Aiyma has ca 50W into 8 ohm (actually only 40, but with 50 I can do the math in my head. And btw your AVR has more so it doesn’t make sense of using the Ayima in the first place). 50W results into 20V output voltage into the speaker. Now take the ca 26dB gain (factor 20) and you land at 1V input voltage to clip the Ayima. Your AVR preouts can easily do that normally. Now if you put the Topping in between and if that happens to add even more gain (I didn’t look into the details but you say it sounds louder), this can easily clip the Ayima and damage your tweeters.

HT Application:
To give you some numbers/facts (not YT anecdotes) why the Ayima is a risk for HT and your speakers even if you keep it directly attached to the AVR preouts.
Assuming your speakers have a sensitivity of around 87dB/W. At 9ft listening distance it takes ca 50W already to get to peaks of ca 96dB SPL and that’s assuming that you listen on average to ca 76dB SPL (remember THX is 85dB average). So those 96dB get the Ayima already to clip. Now what happens if your speaker drops to 4 or even 3 ohms. That more than doubles your power requirement and you are looking at ca 130W or even 266W if that one time you listen extra loud and have peaks of 105dB SPL. Each scenario will more than clip the Ayima, send high energy at high frequencies plus aided by the weird peak in FR response will have a very good chance to overheat and burn out the tweeter of your 4k speaker. Not worth the 90bucks of the Ayima.

The Ayima is a great amp for low/mid level close listening eg an office but not for your application of Home Theater. Again I didn’t look up all the exact numbers but I think the big picture is correct.

i have a question, regarding the sensitivity of the aiyima amps. in my case, it's not important, as i'm using them to drive efficient speakers. but i'm interested in the engineering behind it. if the aiyima, with its high 29db gain, is at risk of over-driving speakers, especially when used in a chain of other components, like avr, volume controlled topping, etc., would it not help if one were to simply reduce the aiyima's volume pot to lower its gain?

and, another comment, re: the aiyima (and fosi) amps, (and the video i mentioned). the amps will put out more power into lower ohms. the speaker designer, demonstrating the amps, had them bridged, which further increases the output. and the a07 max can also be bridged. as you can purchase two of these amps, w/48v/5a power supplies for ~$150 shipped, it's not that expensive. and, as i mentioned before; even if you throw them out, you're not losing a lot of money to try them. also, they will make a bit more power than you state w/bigger power supplies. >100wpc into 8 ohms w/the 48v/5a supply. why would you buy a lesser p/s, when the 48v supply is only a few dollars more?

doug s.

 

[HarmonicTHD]

i have a question, regarding the sensitivity of the aiyima amps. in my case, it's not important, as i'm using them to drive efficient speakers. but i'm interested in the engineering behind it. if the aiyima, with its high 29db gain, is at risk of over-driving speakers, especially when used in a chain of other components, like avr, volume controlled topping, etc., would it not help if one were to simply reduce the aiyima's volume pot to lower its gain?

and, another comment, re: the aiyima (and fosi) amps, (and the video i mentioned). the amps will put out more power into lower ohms. the speaker designer, demonstrating the amps, had them bridged, which further increases the output. and the a07 max can also be bridged. as you can purchase two of these amps, w/48v/5a power supplies for ~$150 shipped, it's not that expensive. and, as i mentioned before; even if you throw them out, you're not losing a lot of money to try them. also, they will make a bit more power than you state w/bigger power supplies. >100wpc into 8 ohms w/the 48v/5a supply. why would you buy a lesser p/s, when the 48v supply is only a few dollars more?
View attachment 349579

doug s.

Yes lowering the volume will help. But you need to measure the output as no one knows exactly what movement of the knob will result in which reduction of gain. Plus if you have kids you better lock it away. Just saying.

Yes with the advanced PS it performs better indeed power wise (the weird FR probably remains I suppose) and would suffice power wise for HT. The OP seemed to have the version tested here with ca 40W into 8 and some 75W into 4ohms afik plus his AVR has around 150 into 4 or so and therefore my recommendation to him.

If one from a reliability point of view would drive 4k speakers permanently is up to everyone individually. I wouldn’t but that is just me of course.

 

[doug s.]

Yes lowering the volume will help. But you need to measure the output as no one knows exactly what movement of the knob will result in which reduction of gain. Plus if you have kids you better lock it away. Just saying.

Yes with the advanced PS it performs better indeed power wise (the weird FR probably remains I suppose) and would suffice power wise for HT. The OP seemed to have the version tested here with ca 40W into 8 and some 75W into 4ohms afik plus his AVR has around 150 into 4 or so and therefore my recommendation to him.

If one from a reliability point of view would drive 4k speakers permanently is up to everyone individually. I wouldn’t but that is just me of course.

Thanks for your reply.

Also, it seems you made this comment, regarding my feeling that the video I mentioned is not worthless, and then deleted it? It showed up in my email notification, and I think it's worth mentioning:

"The video is false and lacks facts. No matter what the motive."

My response to that is that it's not false that he's now using these amps with his speakers at high-end audio shows. Whether or not anyone could actually discern sonic differences in the video is s another story altogether. Of course anyone is free to draw their own conclusions as to why he's now using the amps at audio shows. Because he thinks his speakers sound better? Because the amp mfr is paying him?

doug s.

 

[HarmonicTHD]

Thanks for your reply.

Also, it seems you made this comment, regarding my feeling that the video I mentioned is not worthless, and then deleted it? It showed up in my email notification, and I think it's worth mentioning:

"The video is false and lacks facts. No matter what the motive."

My response to that is that it's not false that he's now using these amps with his speakers at high-end audio shows. Whether or not anyone could actually discern sonic differences in the video is s another story altogether. Of course anyone is free to draw their own conclusions as to why he's now using the amps at audio shows. Because he thinks his speakers sound better? Because the amp mfr is paying him?

doug s.

I deleted it because I realized I wasn’t interested talking more about a ludicrous video where someone babbles about how an amp sounds while listening sighted and non level matched. You had to post my deleted comment nonetheless. Not nice. Nothing I can do about it, but I am out and you are welcome to the last word.

 

[doug s.]

I deleted it because I realized I wasn’t interested talking more about a ludicrous video where someone babbles about how an amp sounds while listening sighted and non level matched. You had to post my deleted comment nonetheless. Not nice. Nothing I can do about it, but I am out and you are welcome to the last word.

again, one can come to one's own conclusions. i think it's telling that he uses this type of amp to demonstrate his own €6,900.00 speakers...

doug s.

 

[springbowtje]

Do I need a 2,1 x 5,5 or a 2,5 x 5,5 connecter to connect my powersupply with the aiyima?

 

[doug s.]

Do I need a 2,1 x 5,5 or a 2,5 x 5,5 connecter to connect my powersupply with the aiyima?

Per aiyima website:
"Power polarity: inside (+) outside (-) (special polarity can be customized according to need)
Plug style: 5.5*2.5mm(Outer diameter: 5.5MM/Inner diameter: 2.5MM/Compatible: 2.1MM)"

doug s.

 

[Guddu]

Do I need a 2,1 x 5,5 or a 2,5 x 5,5 connecter to connect my powersupply with the aiyima?

Ideally 5.5mm x 2.5mm, but 5.5mm x 2.1mm connects as well.

 

[springbowtje]

Ideally 5.5mm x 2.5mm, but 5.5mm x 2.1mm connects as well.

2,5 or 2,1 is the diameter of the inner hole of the connector right? Isn't 2,1 MM not a tighter/better fit with the pin in the aiyima then?

 

[doug s.]

2,5 or 2,1 is the diameter of the inner hole of the connector right? Isn't 2,1 MM not a tighter/better fit with the pin in the aiyima then?

Tighter, yes. Better? Possibly, but there may be a reason 2.5mm is recommended by aiyima.

doug s.

 

[gordoste]

Pretty sure those jacks aren't rated to 48V / 12A (as specified on their website). But it's good value.

 

[doug s.]

Pretty sure those jacks aren't rated to 48V / 12A (as specified on their website). But it's good value.

i've heard that those jacks can't handle 12a; it would be interesting to query aiyima about it. you'd think that if they published the spec, they'd have tested/measured the output of the amp...

doug s,

 

[Guddu]

i've heard that those jacks can't handle 12a; it would be interesting to query aiyima about it. you'd think that if they published the spec, they'd have tested/measured the output of the amp...

doug s,

Where have you seen any details on 12a specification?
They have mentioned 48v 10a max in the table on their portal and Amazon as well.