Aiyima A07 Max Amplifier Review

[billkabb]

Hi, i change the ne5532 opamps with the original muses02 a few days ago and while it sound fantastic i notice that it emphasize the "s" in vocals more than ne5532 and in some cases it is really annoying. i use the smsl su-1 dac , oldies epos m12 speakers and kimper 8tc cables and never had an issue with a/b amps. maybe this class d is more analytical .. anyway has anyone have notice the same results after rolling to muses?

 

[r3uba6HBHa2Ye7F]

is it possible to short the volume pot so it's completely ignored (I will rely on the volume attenuator provided by the preamp). what I'm unsure of is how to turn on the amp then? thanks

 

[Guddu]

is it possible to short the volume pot so it's completely ignored (I will rely on the volume attenuator provided by the preamp). what I'm unsure of is how to turn on the amp then? thanks

Just put the volume knob to max to exclude pot resistance, simply power ON and move the knob to max.

 

[mjosef57]

Anyone know the input impedance of this amp? Read all 24 pages, saw no mention of it nor is it mentioned in the spec sheet.

 

[AIYIMA]

Anyone know the input impedance of this amp? Read all 24 pages, saw no mention of it nor is it mentioned in the spec sheet.

The input impedance is 47k.

 

[Schlippwhip68]

Hi
Is it possible to run the A07 Max in mono with a single op amp as opposed to two needed for stereo and if so which socket would i use?

 

[AIYIMA]

For very small DJ gigs, I now use AIYIMA A07 Pro with 36V/6A PSU coupled with Behringer PK108 pair [8 ohm 320 w max(peak) power].
When turn volume way up i can hear distortions and have shutdowns here and there.
I am thinking about pair of AIYIMA A07 Max in mono mode with 48V/5A PSU pair to replace A07 Pro.
Comments? @staticV3 What do You think? Thank You.

sika

Suggest trying to replace the 48v power supply.

 

[AIYIMA]

Will it work with A07 Max !
Description says - for Fosi v3, v3 mono, ZA3..

48v10a Normal operation 127.4 °F

 

[dr_mick51]

Hi
Is it possible to run the A07 Max in mono with a single op amp as opposed to two needed for stereo and if so which socket would i use?

Absolutely. The top one (closer to back of amplifier) goes to the right channel, and the bottom one goes to the left (I might he wrong, but looking at the pcb traces looks like that's it). You can try removing one opamp (in stereo mode mode) and pay attention to which channel gets quieter than the other.
Once identified the left channel, connect a RCA cable into the left channel on each amp.

 

[mjosef57]

I experienced a one time oscillation using the A07 Max in my biamp set up, however I was unable to repeat that incident.
After 6 hours of continuous use (moderate volume 75-79dB) the A07 Max started oscillating, verified by turning the A07 Max volume down whereas my bass amp had no such sound. Of course I immediately turned it off. And the next day tried to isolate whether it was the preamp. CAT SL1 or the A07 Max or some interaction between them.
First I removed the A07 from the system and went back to my EL84 tube amp, all good no problems after a day of use.
Then I removed the CAT pre and tube amp from the system and using the Topping E50 DAC as the preamp driving the A07 and my bass amp, after a couple days of play and no repeat of oscillation I went back to my original setup with the CAT driving the A07 and bass amp. After two days, all seems good, so I am chalking that incident up to the twilight zone.
The A07 sounds very good, no complaints there, bought this for use as a summer amp, stand in for the tube amp during the hot months.
When I first got it I used it to drive a pair of Alons IV, replacing a Ncore 400 DIY amp, and it did a great job...I was surprised.

My system: Yamaha CD player > Topping E50 DAC >CAT pre > Marchand XM1 crossover > Aiyima A07 Max (@250 Hz./24dB and up), Crown Xti 1002 (bass) > VMPS RM1 speakers. AR The turntable as vinyl source.

 

[Urib]

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. If you are unfamiliar with what is about to follow, please watch my video tutorial:

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

Edit: Bridge Mode Measurements
I put the amplifier in bridge mode (mono) and measured at 4 ohm:
View attachment 329965
Surprising that you don't get much more power. The unevenness in the response is smoothed out though. We get a bit more power if we allow 1% THD:
View attachment 329966

I was told the amp was rated down to 2 ohm in bridged mode which is very unusual. So I gave it a try and it worked to produce a lot more power:
View attachment 329967

Note that majority of speakers I test have their lowest impedance between 3.5 and 4 ohm.

A07 Max Measurements with 48volt/5a Power Supply
Worrying that the power supply may be the limiting factor, I swapped out the 36v/6 amp one for a 48v/5amp unit I had on hand. Let's do a sweep in stereo first:
View attachment 329968

That is nearly 60 watts more power than with the 36 volt power supply. This test is current limited so the extra voltage shouldn't have helped much. It seems to point to the stock power supply not having the 6 amp current it claims. Let's test in stereo where the extra voltage does help:
View attachment 329969

Indeed we get a lot more power (nearly double).

Now let's test in bridged mode:
View attachment 329970
We get more power than with the other power supply but still not what a bridged mode should do. There is also some noise penalty which may be due to different power supply or higher voltage. Here are the 1% THD max and peak powers:

View attachment 329971
This again is far more power than the stock 36 volt one.

EDIT2: Here is the measurement of the included 36v/6amp power supply. First, at rated 6 amp:
View attachment 330129

Fully 6 amps is provided however voltage drops by about 1.2 volts. So instead of ideal 216 watts, we are getting 209 watts.

The power supply was quite robust, allowing me to max out my electronic load's capability of 250 watts:
View attachment 330131

Note that there is further voltage drop so not good for high impedance speaker loads. But for low impedance, we have as much as 7.3 amps out of output without the supply shutting down.

EDIT 3:
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.

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.

------------
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/

Does anyone tried working with these amps in mono mode using 48v 10a power supply?

 

[Mavenbolt]

Hello everyone!

I recently found this amplifier for cheap on AliE (Around 50 USD inc shipping), and I decided to get it as a replacement for my old DIY TPA3116 board.

I noticed that this Amp uses two NE5532s, and I have a pair of OPA2132PAs sitting around without use, I initially got them for a Cmoy project that I almost never used.

Has anyone tested/measured if such OpAmps could improve the characteristics of this amplifier? Or is there any specific capacitor mods that would give better results? I couldn't find specific info for those OpAmps in this application.

I plan to use a FiiO BR13 as receiver/Dac for it.

 

[dr_mick51]

Hello everyone!

I recently found this amplifier for cheap on AliE (Around 50 USD inc shipping), and I decided to get it as a replacement for my old DIY TPA3116 board.

I noticed that this Amp uses two NE5532s, and I have a pair of OPA2132PAs sitting around without use, I initially got them for a Cmoy project that I almost never used.

Has anyone tested/measured if such OpAmps could improve the characteristics of this amplifier? Or is there any specific capacitor mods that would give better results? I couldn't find specific info for those OpAmps in this application.

I plan to use a FiiO BR13 as receiver/Dac for it.

Those opamps are compatible. Try swapping them and decide if they are worth it.
Yes, you can try replacing (if you feel confident enough with the soldering iron) the coupling capacitors (10uF) for better ones if you want and let us know what you think(hear).

 

[morozzz_2003]

Hi all! I have a question about max power after comparing table on 1 page…
Amp and power supply 48v 10a
I have 8 ohm speaker 100 w (Tannoy Mercury V4i)
1 amp gives in stereo 185*2
2 amps in mono gives 190w*1
I think it makes no sense to buy a second amplifier... It`s right?
And one thing, 8 ohms 190\185 w - same power for 5a and 10a... it`s correct?

 

[Mavenbolt]

Those opamps are compatible. Try swapping them and decide if they are worth it.
Yes, you can try replacing (if you feel confident enough with the soldering iron) the coupling capacitors (10uF) for better ones if you want and let us know what you think(hear).

I noticed that my old TPA3116 modded has better mid-bass response than this one that seems a bit muddy...

So I tried the OPA2132PAs I have, and the whole frequency response sounded better, principally the mid bass until I put something with more kick to play and noticed some distortion. I wonder if this can be caused due to the low quality caps or just my E10K TC giving out more voltage in it's Line Out than the Amp can handle.

About the capacitors, just to be sure, I have the V2 board. The capacitors C6, C33, C36, C39 and C20 are all tiny 100V capacitors.

I do have some Wima 1.5 UF 100V film caps, do I change all of them for that? (I also have some 1uf ones but they're 63V)

In case I'd need the .1UF, I have some film caps as well, but they're 63V, would that work without issues?

Thank you for the help!

 

[Mavenbolt]

To add a bit more information, here's an image of how my old 3116 was.

From those components, the only things I can say with 100% certainty are original is the 1UF brown Panasonic Caps, the Wurth Inductors, the TPA chips themselves and the small ceramic capacitors under the kapton tape, also from Wurth. I got 2 3116 samples from TI and used them here.

The Wima and nichicon ones were bought from AliExpress, just like the board. There's a bunch of traces broken from fiddling too much with it, hence why I decided to invest in the A07 Max. Also this board is housed in a simple electronic plastic shell, it looks pretty rough on my table.

 

[dr_mick51]

I noticed that my old TPA3116 modded has better mid-bass response than this one that seems a bit muddy...

So I tried the OPA2132PAs I have, and the whole frequency response sounded better, principally the mid bass until I put something with more kick to play and noticed some distortion. I wonder if this can be caused due to the low quality caps or just my E10K TC giving out more voltage in it's Line Out than the Amp can handle.

About the capacitors, just to be sure, I have the V2 board. The capacitors C6, C33, C36, C39 and C20 are all tiny 100V capacitors.

I do have some Wima 1.5 UF 100V film caps, do I change all of them for that? (I also have some 1uf ones but they're 63V)

In case I'd need the .1UF, I have some film caps as well, but they're 63V, would that work without issues?

Thank you for the help!

Those capacitors you are mentioning are the Supply Voltage bypass caps used to filter high frequency noise on the supply, and Trung tried changing them for ceramic and Film caps with good results. I don't see a problem installing 63V film caps here (when max 48V is used). These are the ones circled in blue.

The audio coupling capacitors I meant to be changed are the 6 Electrolytic capacitors cicled in red. 2 are used to couple the signal coming from RCA connectors(ones 9n the left), the other 4 are for the signal coupling after the OPAMPs and before the TPA chip.

 

[Mavenbolt]

Those capacitors you are mentioning are the Supply Voltage bypass caps used to filter high frequency noise on the supply, and Trung tried changing them for ceramic and Film caps with good results. I don't see a problem installing 63V film caps here (when max 48V is used). These are the ones circled in blue.

The audio coupling capacitors I meant to be changed are the 6 Electrolytic capacitors cicled in red. 2 are used to couple the signal coming from RCA connectors(ones 9n the left), the other 4 are for the signal coupling after the OPAMPs and before the TPA chip.

Thank you very much for your input and time!

I am using a Meanwell LRS350 48V set to it's minimum voltage (It's around 42V) to avoid heating the amp too much.

I will change the Supply bypass caps for the film ones I have, I really don't mind being overzealous with those as I have a couple caps laying around from modding my previous 3116.

In regards to the electrolytics (Elnas), is there any optimal value to use for them, and is film caps ok too?

I can change them all for 1,5uF 100V Wima caps, I also have some 10uF 50V Nichicon Muses green caps, but I am unsure if the high capacitance will do anything for it. My experiences with my previous 3116 is that those 10uF nichicons would add some distortion to it, while up to 2.2uF film caps were totally fine (but again... I'm understand very little about it all tbh...)

I would just like to avoid swapping caps multiple times to avoid damaging the board like I did with my previous one haha


Also, the 2 ELNA caps near the white relay are not in the audio path? Is it necessary to change them?

 

[dr_mick51]

Thank you very much for your input and time!

I am using a Meanwell LRS350 48V set to it's minimum voltage (It's around 42V) to avoid heating the amp too much.

I will change the Supply bypass caps for the film ones I have, I really don't mind being overzealous with those as I have a couple caps laying around from modding my previous 3116.

In regards to the electrolytics (Elnas), is there any optimal value to use for them, and is film caps ok too?

I can change them all for 1,5uF 100V Wima caps, I also have some 10uF 50V Nichicon Muses green caps, but I am unsure if the high capacitance will do anything for it. My experiences with my previous 3116 is that those 10uF nichicons would add some distortion to it, while up to 2.2uF film caps were totally fine (but again... I'm understand very little about it all tbh...)

I would just like to avoid swapping caps multiple times to avoid damaging the board like I did with my previous one haha


Also, the 2 ELNA caps near the white relay are not in the audio path? Is it necessary to change them?

The TPA3255 schematics show 10uF as the correct value for those coupling caps and they affect the high pass frequency. Not sure what the TPA3116 requires, but would not use anything less than 10uF for the TPA3255.
The problem with high quality electrolytics is that the leads are thicker and sometimes don't fit the pcb holes.
The other electrolytics you mentioned I think are 100uF(too big for audio coupling caps) on my amp and I dont think are on the signal path, more likely are decoupling caps for the opamps supply voltage. I replaced all of them with Nichicon UKW 10uF and 100uF.
Not sure if right or not, but I assume all these stock capacitors are not the "best" quality. Replacing them is part of the hobby and I enjoy it.

 

[Mavenbolt]

The TPA3255 schematics show 10uF as the correct value for those coupling caps and they affect the high pass frequency. Not sure what the TPA3116 requires, but would not use anything less than 10uF for the TPA3255.
The problem with high quality electrolytics is that the leads are thicker and sometimes don't fit the pcb holes.
The other electrolytics you mentioned I think are 100uF(too big for audio coupling caps) on my amp and I dont think are on the signal path, more likely are decoupling caps for the opamps supply voltage. I replaced all of them with Nichicon UKW 10uF and 100uF.
Not sure if right or not, but I assume all these stock capacitors are not the "best" quality. Replacing them is part of the hobby and I enjoy it.

I like doing this type of modding too. The 3116 is 1uF, up to 2,2uF you get flat response below 20Hz.

I'm skeptical of trying my Muse Capacitors, they're 10uF 50V but Bipolar. I see that all capacitors on the audio path for this board are polarized, so I might keep the Elnas for now, but I definitely notice the high end being held back a bit.

I managed to swap the electrolytic caps for film ones, the soldering job isn't great, but it's all connected properly.

Getting any type of decent 10uF polarized cap where I live is almost impossible, or just absurdly expensive. The only feasible option I could try is LCSC. I found some 10uF caps there from Rubycon, but I'm not sure they're good ones for audio...

The caps near the white relay? Those are the same value as all other elnas on my amp, 4.7uF 25V, that's why I thought they were in the audio path too.

Edit: I looked at the schematic and noticed that the 3255 does accept the usage of non polarized capacitors for the input, and I swapped those 6 caps for the Nichicon Muse I had, the soldering job was painful since they were used and had short legs, but I managed to secure them in.

Honestly maybe they're just "bad" caps like the Elnas, in lower volume I can't hear any difference. I even attempted swapping back to the NE5532 the amp came with, it did improve a bit the high end response, but the overall sound with the OPA2132s are just warmer in a way I prefer.

Since it's late now I can't really push the volume, but I will test it tomorrow in higher volume.