Aiyima A07 Max Amplifier Review

[T&T]

Aiyima A07 vs A07 Max stereo vs A07 Max mono x2

AIYIMA A07 MAX - KING OF SPEED & PUNCH

There you Go... the Reason why I sold my Fosi V3, Aiyima07 Max sound Amazing with Muses02 rather than Sparkos ss3602

 

[trungdtmc]

Inductor temp, amp idle no signal in, 48v supply, room temp 22*C. Quite hot right?

 

[MCH]

Inductor temp, amp idle no signal in, 48v supply, room temp 22*C. Quite hot right?
View attachment 356395

Remember the enclosure is the heat sink. Not sure if having the board open will make it better or worse,

I had 2 a07 max running side by side one with 36V and the other with 47V. The difference in temperature was significant. Lowered 47 to 42V and now there is almost no difference.

 

[dr_mick51]

Inductor temp, amp idle no signal in, 48v supply, room temp 22*C. Quite hot right?
View attachment 356395

On both dual inductors? What is your power consumption?. 30degC above ambient temp do not seem excessive.
Those inductors have aprox 10mOhm DCR, and can hold up to 7A before internal temperature increases 40Degrees.
I^2*R= 49*0.01=0.49W dissipation.
This would mean the amplifier outputs 49*4Ohm=196W per channel.
I asked the other inductor temperature to confirm is not the thermistor heating up the inductor. That thermistor gets very hot.

 

[trungdtmc]

Remember the enclosure is the heat sink. Not sure if having the board open will make it better or worse,

I had 2 a07 max running side by side one with 36V and the other with 47V. The difference in temperature was significant. Lowered 47 to 42V and now there is almost no difference.

These inductors do not direct contact with the cover. The picture is that I measured the temperature immediately after taking it off because I felt it was very hot before

On both dual inductors? What is your power consumption?. 30degC above ambient temp do not seem excessive.
Those inductors have aprox 10mOhm DCR, and can hold up to 7A before internal temperature increases 40Degrees.
I^2*R= 49*0.01=0.49W dissipation.
This would mean the amplifier outputs 49*4Ohm=196W per channel.
I asked the other inductor temperature to confirm is not the thermistor heating up the inductor. That thermistor gets very hot.

Both dual inductors have the same temperature when the amp does not have input signal. I will try to measure again when generating higher power levels at 4ohm load.
My modded A07 has a much lower inductor temperature even though it operates at 600khz

 

[Cal_Cobra]

Long time lurker, but after reading all twenty pages of this thread, I had to post I've been a HT enthusiast going back to Dolby Pro Logic and Pioneer Laser Discs, but have recently been having a blast getting back into the stereo world testing hybrid tube amps and class D chip amps. Their ridiculous low price points enables HiFi enthusiast to experience a wider range of boutique audio products.

Given the ridiculous low price of the AIYIMA A07 Max when on sale (like now), I grabbed a couple for $50 each delivered! I also picked up a pair of these power supplies on the AE sale to run them - High-power digital audio amplifier board DC48V 7.3A 350W Power Board Amplifiers Switching Power Adapter. I believe they're identical (likely the OEM) of the same optional power supplies sold for the A07 Max in the AIYIMA shop. These power supplies will be connected to a Monster Power HTS5000 Mark II Reference Power Center, and I ordered the optional upgraded GX16 DC 5.5 X 2.5mm silver plated power cables with gold plated power connectors. The power supplies will use a pair of Preffair 13AWG OFC copper Schuko power cables to connect to the Monster Power HTS5000 Mark II Reference Power Center.

I plan to run them in mono mode, and will use this One Little Bear Douk Audio EQ5 PRO as my pre-amp:

This is going to be fun!

 

[springbowtje]

I have 2 of these amps in mono powered by 1 powersupply. I hear a noise through my speakers with the volume at max and no input. Even when I have only one A07 max on, I hear this noise. When I remove the powerplug from the other aiyima or I disconnect the rca from the other A07 max not in use, the noise is gone. So with only one aiyima in mono mode I have noise, when I connect both I have noise even when one in not powered on. I tried a different powersupply, with or without earth at the powersupply, connected the rca's with another source but nothing helps. Does anybody knows what's going on and how to get rid of it?

 

[doug s.]

I have 2 of these amps in mono powered by 1 powersupply. I hear a noise through my speakers with the volume at max and no input. Even when I have only one A07 max on, I hear this noise. When I remove the powerplug from the other aiyima or I disconnect the rca from the other A07 max not in use, the noise is gone. So with only one aiyima in mono mode I have noise, when I connect both I have noise even when one in not powered on. I tried a different powersupply, with or without earth at the powersupply, connected the rca's with another source but nothing helps. Does anybody knows what's going on and how to get rid of it?

have you tried using a separate p/s for each amp?

doug s.

 

[springbowtje]

have you tried using a separate p/s for each amp?

doug s.

No I haven't. I had a 36v 7A power supply with my aiyima a07 but bought a quality 48v mornsun lof550 for the two A07 max in mono.

 

[doug s.]

No I haven't. I had a 36v 7A power supply with my aiyima a07 but bought a quality 48v mornsun lof550 for the two A07 max in mono.

you should try running each amp on its own power supply. (also try each p/s on a single amp connected in stereo.)

and, i'd also recommend a separate p/s for each amp, even if there were no hum, and/or you get the hum issue sorted out. something like a pair of Mean Well HRP-300-48's would cost less than the single p/s you bought, if you shop carefully, and would have better amperage capacity per channel, as well as truly separate amps for each speaker. why share a power supply?

doug s.

 

[dr_mick51]

I have 2 of these amps in mono powered by 1 powersupply. I hear a noise through my speakers with the volume at max and no input. Even when I have only one A07 max on, I hear this noise. When I remove the powerplug from the other aiyima or I disconnect the rca from the other A07 max not in use, the noise is gone. So with only one aiyima in mono mode I have noise, when I connect both I have noise even when one in not powered on. I tried a different powersupply, with or without earth at the powersupply, connected the rca's with another source but nothing helps. Does anybody knows what's going on and how to get rid of it?

Not sure if I understand correctly. But one way to find out is swapping RCA cables to see if the noise follows the rca cable, or also try swapping the amps to see if the noise follows on specific amp.
Did you try each amp independently in mono? And then each one independently in stereo?.
I'm trying to figure out if one of the amps is defective. Also you can try a different pair of rca cables.

 

[springbowtje]

Not sure if I understand correctly. But one way to find out is swapping RCA cables to see if the noise follows the rca cable, or also try swapping the amps to see if the noise follows on specific amp.
Did you try each amp independently in mono? And then each one independently in stereo?.
I'm trying to figure out if one of the amps is defective. Also you can try a different pair of rca cables.

Only one amp in mono or stereo is no problem. The noise is only there when I connect both amps in mono. Even when in that configuration one amp isn't powered on. When I remove the rca cable or power supply from one of the amps, the noise is gone.
Used my nad t757 as preamp and tried with the preouts from my blueray player also to be sure my nad wasn't the problem.

 

[springbowtje]

you should try running each amp on its own power supply. (also try each p/s on a single amp connected in stereo.)

and, i'd also recommend a separate p/s for each amp, even if there were no hum, and/or you get the hum issue sorted out. something like a pair of Mean Well HRP-300-48's would cost less than the single p/s you bought, if you shop carefully, and would have better amperage capacity per channel, as well as truly separate amps for each speaker. why share a power supply?

doug s.

Because I asked here before ordering and it was confirmed as good.
Because I wanted to try a decent power supply instead of the cheap AliExpress ones.
Because the mornsun lof550 is recommended on this forum and is used in different diy builds in this forum. Also to power one or more tpa3255 amp boards.

 

[doug s.]

Because I asked here before ordering and it was confirmed as good.
Because I wanted to try a decent power supply instead of the cheap AliExpress ones.
Because the mornsun lof550 is recommended on this forum and is used in different diy builds in this forum. Also to power one or more tpa3255 amp boards.

you still need to try these amps w/separate power supplies when running mono, to see if this is the cause of the noise.

and, regardless of what you've been recommended before, using good separate power supplies - one for each amp - will always give better results than using one power supply for two amps. i was considering buying the the mean well p/s that i mentioned, (also excellent power supplies), for my two amps, (i'm running them both in stereo, in a quad-amped set-up), but i decided it was overkill for the drivers, and the stock 48v/5a p/s's would be sufficient, since the drivers are >95db/1w efficient.

doug s.

 

[dr_mick51]

Only one amp in mono or stereo is no problem. The noise is only there when I connect both amps in mono. Even when in that configuration one amp isn't powered on. When I remove the rca cable or power supply from one of the amps, the noise is gone.
Used my nad t757 as preamp and tried with the preouts from my blueray player also to be sure my nad wasn't the problem.

The RCA negative wires and power ground are connected. Try using different power supplies for each amp. You are having a ground loop.

 

[doug s.]

The RCA negative wires and power ground are connected. Try using different power supplies for each amp. You are having a ground loop.

agreed; which is why i made the suggestion earlier, and repeated it again. i'd imagine the op is a bit disappointed spending the coin on a nice p/s and having this happen. and, for me, even w/if no ground loop issue, i'd rather have two 48v/7a power supplies for two amps than a single 48v/11a power supply.

doug s.

 

[dr_mick51]

The RCA negative wires and power ground are connected. Try using different power supplies for each amp. You are having

Only one amp in mono or stereo is no problem. The noise is only there when I connect both amps in mono. Even when in that configuration one amp isn't powered on. When I remove the rca cable or power supply from one of the amps, the noise is gone.
Used my nad t757 as preamp and tried with the preouts from my blueray player also to be sure my nad wasn't the problem.

Let me tell you about something that happened to me like a year ago. I have an A/B/C/D speaker switch. 1 speaker cable set input and 4 speaker set cables output that you can control to play on output A, or B or both at the same time. It is basically to test speakers and identify differences on how they sound. Then I though what about if instead of using it as a 1 input and 4 output switch, I wire it as 4 inputs and 1 output. This way I can test up to 4 amplifiers and play on the same speaker set. Well...let me tell you It did not work. I was getting a loud ground loop no matter which amplifier I select. It turned out that all the negative wires were connected(even if I select none from the switches) and only the positive wires were affected by the switches I select.

 

[saberger0357]

Probably has been stated elsewhere, but can I confirm that both the V3 and ZA3 will produce more watts at 4 ohms then the A07 Max run in mono?

 

[staticV3]

Probably has been stated elsewhere, but can I confirm that both the V3 and ZA3 will produce more watts at 4 ohms then the A07 Max run in mono?

With all three Amps powered by a 48V5A supply, the 4Ω output power "at the knee" is:

Stereo:
A07 Max___140W
V3_________140W
ZA3________140W

Mono:
A07 Max___166W
ZA3________200W

 

[saberger0357]

With all three Amps powered by a 48V5A supply, the 4Ω output power "at the knee" is:

Stereo:
A07 Max___140W
V3_________140W
ZA3________140W

Mono:
A07 Max___166W
ZA3________200W

Ah ok. Thanks!