Aiyima A07 Max Amplifier Review

[donahana]

Warning, complete noob here but I do have a few questions.

Found a pair of Dali Oberon 1 locally but still quite lost as to which amplifier to use. It's for desktop usage so the smaller/lighter the better, if i can plug it into the TV via optical/BT it'd be nice though it's not mandatory, room is 10m², speakers are 90cm~ away or roughly 3m when watching TV though as said earlier, if not possible to use it on the TV as well it's not mandatory. Planning on adding a subwoofer later and keep it 2.1 forever.

I've searched for amplifiers locally but I've only found those huge integrated amps like the Marantz PM6007 ($675), Yamaha A-S301 ($550) and A-S501 ($845), Cambridge AXA35 ($510 or $380 used) , Onkyo A9110 ($575) etc which seem quite overkill for my case (as well as bulky) so I'm thinking of going with a more budget option and these chinese amps caught my eye.

Would this amp be an adequate choice considering I don't need a ton of connectivity for multiple devices or more power to fill a giant room? I've read and from the little I understood it seems I can just plug any active subwoofer on the aux out and be done with a great-sounding 2.1 setup. Did I get anything wrong? And are there any better or more interesting options with a budget of up to $200? What if I up that to $300 or $400? Also have a Topping DX1 if it helps in any way.

 

[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.

So, I've been testing things for a while now, and I'd like to share my experiences with what I tested here that might be of interest to you (and the community).

First of all, the first ELNA caps you didn't circle are indeed part of the audio path, and not part of the power supply for the OpAmps.

I had to change them as well to 10uF capacitors to finally hear the difference.

So those 8 capacitors seem to be part of the audio path I changed them either way to the same capacitors, 10uf 50v Nichicon FG (possibly fakes, but they sound really good right now, got them from Ali)

Now about the OpAmps, I throughly listened to both over the past weeks, not sure how I didn't end up scratching my amp doing that.

The OPA2132 pushes the vocals too forward in this circuit. Almost like a inverted "V" curve. Both lows and highs take a step back for the vocals.

It weirded me out and took more time to accept this as fact than I'd like. In a old very simple preamp I made they also improved bass response when comparing to no preamplifier in the TPA3116 circuit.

The NE5532 ended up sounding way better, the highs and lows sound more balanced. Maybe the highs are a bit too forward with the capacitor change, but it doesn't get to the point it hurts to hear. So OPA2132 vs NE5532, NE5532 wins here.

 

[ICIETDIYEUR]

Hello.

Has anyone performed THD+N measurements with other OpAmps than the original NE5532 ?

I think this should have an impact on the SINAD rating of this amplifier, right ?

 

[rickpref]

New here, but have read many posts in ASR since it pops up in Google all the time when researching different products.

I bought 1 A07 Max with the 48V5A power supply to connect my L/R to my Onkyo NR696. I liked how much the sound improved that I bought a second for my center with the 48V10A to try and match the power between the 3 speakers. It really blows the Onkyo amp's sound quality away. Eventually I'll get a proper amp, but got into this cheap getting just the one amp first.

I've been setting the volume of the amps with an spl meter and then using the receiver to control power.

Should I set the power of the amps to max and then adjust the levels on the receiver or would that add distortion to the sound coming from the amps.

 

[Guddu]

Should I set the power of the amps to max and then adjust the levels on the receiver or would that add distortion to the sound coming from the amps.

Yes, it would be ideal as you won’t need to remember or re-seat the volume knob to similar position and keeping volume knob to max takes any effect of potentiometer out in theory.

 

[rickpref]

Yes, it would be ideal as you won’t need to remember or re-seat the volume knob to similar position and keeping volume knob to max takes any effect of potentiometer out in theory.

Thanks for the reply. That's what I figured, just wondering if raising it to max adds distortion or not. The way I have them around 75% or so turning them off is a pain the ass, so they've just been on 24/7.

 

[Guddu]

Thanks for the reply. That's what I figured, just wondering if raising it to max adds distortion or not. The way I have them around 75% or so turning them off is a pain the ass, so they've just been on 24/7.

You aren’t feeding your amp in to run to its limits, I hope, as you control volume or input on your DaC/pre-amp/AVR.
So distortion shouldn’t be an issue beyond its parameters.
I run it same way with my Emotiva XMC-1 for center channel.
@AIYIMA
I miss triggered input or some sort of auto sensing, but I make it up with a smart plug/switch so I don’t have to touch the volume knob again and again.

 

[staticV3]

Thanks for the reply. That's what I figured, just wondering if raising it to max adds distortion or not.

Turning the Aiyima's volume knob to Max does not inherently add distortion.

The only thing that adds distortion is appraching the Amp's output limits, be that with low input signal+high Amp volume, or high input signal+low Amp volume.

 

[rickpref]

You aren’t feeding your amp in to run to its limits, I hope, as you control volume or input on your DaC/pre-amp/AVR.
So distortion shouldn’t be an issue beyond its parameters.
I run it same way with my Emotiva XMC-1 for center channel.
@AIYIMA
I miss triggered input or some sort of auto sensing, but I make it up with a smart plug/switch so I don’t have to touch the volume knob again and again.

Yeah, setting the AVR volume to about 60 out of 100 is the highest I can get with the amps set to max without distortion. I guess I need to set a volume limit on the AVR in case someone comes in and slams the volume up too high, lol.

 

[rickpref]

Turning the Aiyima's volume knob to Max does not inherently add distortion.

The only thing that adds distortion is appraching the Amp's output limits, be that with low input signal+high Amp volume, or high input signal+low Amp volume.

That's mainly what I wanted to know...thanks!

 

[Mavenbolt]

Hey guys, sorry if this might be a common thing or similar, I'm not too experienced with electronics.

I recently tried to use my FiiO BR13 EQ to bump the bass a bit, but immediately noticed distortion, even at levels below 1db would still give me somewhat odd distorted bass. This happens even in very low volumes as my speakers are pretty close to me on my desk PC.

I have 2 other amplifiers I tested with the BR13, and even up to 2db boost in bass resulted in clean output from my LM3886 and TPA3116 based amplifiers.

I then decided to put a cheap scope (one of those DS150 DIY ones) on the output and noticed a constant 47~49khz signal showing up and actually putting around 0.65v AC in the output of my A07 Max. This doesn't happen with the LM3886 or TPA3116.

I have tried using the same Meanwell PSU from the 3116 in the A07 but got the same results.

Also tried another Dac, no dac, no speakers, a 4ohm resistor but it just stayed there.

Is this normal? I understand I changed a couple of capacitors, but nothing I did really changed this.

Any input is very appreciated as I dont know if this could damage my speakers or be the reason why my Aiyima gets kinda warm (around 37~40c) even idle.
Edit: image showing the scope measurement, no inputs or outputs plugged (it doesn't change them being there or not)

 

[musica]

Aiyima A07 Max can I use it as a stereo power amplifier and my Denon pma 700 ae integrated amplifier as a preamplifier?

 

[staticV3]

Aiyima A07 Max can I use it as a stereo power amplifier and my Denon pma 700 ae integrated amplifier as a preamplifier?

Yes.

Denon Pre Out->RCA->A07 Max.

 

[musica]

Yes.

Denon Pre Out->RCA->A07 Max.

Is the miniDSP okay between the Denon and the A07 Max, so I can control the volume of the satellite speakers and an active sub using just the Denon knob?

 

[staticV3]

Is the miniDSP okay between the Denon and the A07 Max, so I can control the volume of the satellite speakers and an active sub using just the Denon knob?

Yes.

 

[musica]

Does the A07 Max replace the Denon well as a power amplifier? Are there any risks to my speakers?

 

[tommy6]

I'm going to ask an extended question.
Last year the machine was turned on until today, and went very hot to the touch.
In addition to the smart plug
Does everyone how to turn off the power.
My DAC automatically detects and adjusts the power which is really convenient!

 

[ICIETDIYEUR]

Hi tommy6

Regarding the heat to the touch of your AIYIMA A07 MAX, what power supply do you have ?

Or rather, we should ask the question differently:
- What is the impedance of your speakers ?
- How much power do you need ?

Here is a table about PSUs ->

Explanation:

The TPA 3255 (amplifier chip) in your amplifier works best at its maximum frequency AND maximum voltage.

However, you have to take into account the heat dissipation surface (here the box in direct connection with the chip heatsink) of your amplifier which is rather small in consumer amplifiers (such as the FOSI AUDIO V3 for example).

So, what I say above is NOT APPLICABLE because indeed, and you have noticed it: your device will become too hot !

It is therefore advisable to take a power supply with the lowest voltage on the board according to your needs, which will limit this heat dissipation as much as possible.

You can also increase the space between the bottom of your amplifier and the surface it sits on, this helps a bit with cooling.

To cut off the power supply to your amplifier, the best thing to do is to do it manually while waiting for an additional box allowing the amplifier to be switched off without the presence of a signal or for manufacturers to integrate this original function into their device, a bit like the 12V TRIGGER socket that exists on some.

But if you search on AMAZON, there are TRIGGER 12V driven IEC sockets that could be a solution....

 

[tommy6]

Hi tommy6

Regarding the heat to the touch of your AIYIMA A07 MAX, what power supply do you have ?

Or rather, we should ask the question differently:
- What is the impedance of your speakers ?
- How much power do you need ?

Here is a table about PSUs ->

View attachment 387184

Explanation:

The TPA 3255 (amplifier chip) in your amplifier works best at its maximum frequency AND maximum voltage.

However, you have to take into account the heat dissipation surface (here the box in direct connection with the chip heatsink) of your amplifier which is rather small in consumer amplifiers (such as the FOSI AUDIO V3 for example).

So, what I say above is NOT APPLICABLE because indeed, and you have noticed it: your device will become too hot !

It is therefore advisable to take a power supply with the lowest voltage on the board according to your needs, which will limit this heat dissipation as much as possible.

You can also increase the space between the bottom of your amplifier and the surface it sits on, this helps a bit with cooling.

To cut off the power supply to your amplifier, the best thing to do is to do it manually while waiting for an additional box allowing the amplifier to be switched off without the presence of a signal or for manufacturers to integrate this original function into their device, a bit like the 12V TRIGGER socket that exists on some.

But if you search on AMAZON, there are TRIGGER 12V driven IEC sockets that could be a solution....

Hello:

1.Impedance (Ohm) 4.
2.speaker specs are IEC Power Handling (W) 150.
I'm currently using the default 36V a
nd the normal standby temperature is about 50 degrees Celsius, so it would be nice to have a detection or auto shutdown setting.

 

[ICIETDIYEUR]

Hello tommy6

I think the temperature of your amplifier seems a little too high for use with a 36Volt transformer (hopefully it's a 6Amperes).

With 4Ohms impedance speakers you should get about 120Watts (with THD 1%) before 'clipping'.

It seems to me that first of all it would be necessary to replace the thermal paste between the TPA3255 and its heatsink and also to raise the bottom of the amplifier chassis with small, thicker rubber pads: this should already contribute significantly to lowering the temperature of the amplifier.