AIYIMA A07 TPA3255 Review (Amplifier)

[GNK]

The answer to your question is contained in the datasheet for the TPA3255 chip -
https://www.ti.com/lit/gpn/tpa3255
In stereo mode the chip is already configured as bridge-tied load. For mono the chip needs to be in parallelled
Sure, you could follow the schematics and modify your AIYIMA A07 board to reconfigure it for PBTL - see page 28 of the datasheet.
But this is delicate work, and you risk damaging the board.
I suggest it's far more sensible to just buy the mono version of the A07, which AIYIMA already provides as model A3001 -
https://www.aiyima.com/products/subwoofer-amplifier-aiyima-a3001

Thanks! You saved my day

 

[L7R]

3dB out of balance and somebody would buy this? 0,5dB is audible difference. People complains about distortion, samplerates, frequency ranges, decoders etc, but then they will not when their music comes 3db out of balance? World is going crazy.

How can Amir recommend this? At least it should come with a balance-knob.

 

[staticV3]

@L7R where are you seeing 3dB channel imbalance?

 

[Badunn]

Well I just pushed the button on an A07. It will take the amplifier duties from my Arcam SR250 using it's pre out. At £80 from Amazon I figured it's worth a punt. I had to seek advice on how to wire my BK active subs (hi level stereo pair) but that's now been sorted with help from REL helpline.
I listen at modest levels through my Tannoy XT6F floor standers - and if an improvment is perceived I may purchase a higher power brick, or a second A07.
Not sure what to expect. Will report back

 

[pixelgarden]

what was the total cost of all the mods?

Roughly 45$ for all mods included. But I already had most of the parts, i only purchased OP AMP & those little 9 capacitors for my mod.

 

[El Cheapo]

A07 Power testing by Williston Audio

 

[TonyJZX]

yeah that is an absolutely amazing performance with the $75 48v transformer

i mean where else can you get a 100-110-120w at this kind of performance and clarity for that kind of money

its not close to sota but donking units twice or three times the price

 

[TheWalkman]

I hadn’t used my A07 in awhile, but this thread motivated me to hook it up for a run. It’s powered by a Mean-Well 48V brick, pushing a pair of Elac DBR62‘s and being driven from an Amazon Alexa.

I’d forgotten how this little amp rocks.

For someone wanting to get into hi-fi on a modest budget, this is a great entry point.

 

[SmackDaddies]

3dB out of balance and somebody would buy this? 0,5dB is audible difference. People complains about distortion, samplerates, frequency ranges, decoders etc, but then they will not when their music comes 3db out of balance? World is going crazy.

How can Amir recommend this? At least it should come with a balance-knob.

What?

And 3db is the perceived difference threshold for most people, and many can't hear a difference until 5db.

source

 

[Grooved]

What?

And 3db is the perceived difference threshold for most people, and many can't hear a difference until 5db.

source

This source is talking about the general perceived volume, not a difference between L and R channels (and I don't find any link to the studies they are talking about).
Even if we suppose that it's an average among people, it's more saying that you need to have both L and R decrease or increase by 5dBA to notice the change.

It has nothing to do with one channel being 3dB lower than the other channel, because it's not the same thing you're perceiving here.
With one channel being 3dB lower, the first effect if that all that should be centered won't be centered anymore

 

[grogi.giant]

The Aiyima D05 has more functions and features, but maybe not as low distortion for some applications. The TAS5352 amplifier IC is very old (current TAS5352 DS is 2007) and is NOT recommended for new designs.

Aiyima D05 Chips set: CM6642, TAS5508, TAS5352A, QCC3008, CS8422, WM8782

Actually it is TAS5352A. Spec sheet was revised in 2016. It still is active and fully supported, also for new designs.

What is really old is the PWM Processor - TAS5508. It is alsmost two decades years old at this stage (introduced in 2004).

 

[san]

Hi,

I bought this amp few days before. I noticed mild shock when touching the amp. When checked with a tester I see current passing through the whole body of the amp and it's affecting the whole chain.

Should I replace the device. Please advise.

Note: I have used other amps Fosi, SMSL. I never faced this issue.

 

[Toku]

Hi,

I bought this amp few days before. I noticed mild shock when touching the amp. When checked with a tester I see current passing through the whole body of the amp and it's affecting the whole chain.

Should I replace the device. Please advise.

Note: I have used other amps Fosi, SMSL. I never faced this issue.
View attachment 262134View attachment 262135View attachment 262136

A half voltage of the power supply voltage is applied to the speaker terminal of the BTL type amp. Therefore, the voltage detector operates at the speaker terminal. However, it is clearly abnormal that the voltage detector operates even in the power switch part.
My guess is that there is a problem with the AC power adapter.

 

[Roland68]

Hi,

I bought this amp few days before. I noticed mild shock when touching the amp. When checked with a tester I see current passing through the whole body of the amp and it's affecting the whole chain.

Should I replace the device. Please advise.

Note: I have used other amps Fosi, SMSL. I never faced this issue.
View attachment 262134View attachment 262135View attachment 262136

Please measure the amplifier alone, without connected loudspeakers and RCA cables.
Is there still AC voltage on the housing and the connections?

 

[Triliza]

I got one of this and it has the same problem, I measured and the voltage is around 11 volt in on-off switch and the screws in the front. It doesn't seem to be any current in the chassis (0.6 V). I'd like also to know what can be done, is it something we can fix ourselves? Would a power supply from a laptop work for testing purposes, assuming it is the power supply? I'm in no mood to go through the return process, bought it at amazon.de. I'm using the stock 32V 5A power supply that came with it.

 

[san]

Please measure the amplifier alone, without connected loudspeakers and RCA cables.
Is there still AC voltage on the housing and the connections?

Checked that, still the same.

 

[trungdtmc]

I got one of this and it has the same problem, I measured and the voltage is around 11 volt in on-off switch and the screws in the front. It doesn't seem to be any current in the chassis (0.6 V). I'd like also to know what can be done, is it something we can fix ourselves? Would a power supply from a laptop work for testing purposes, assuming it is the power supply? I'm in no mood to go through the return process, bought it at amazon.de. I'm using the stock 32V 5A power supply that came with it.

12v power supply for opamps works as soon as mains is supplied, no need to turn on the switch

 

[Roland68]

Checked that, still the same.

I got one of this and it has the same problem, I measured and the voltage is around 11 volt in on-off switch and the screws in the front. It doesn't seem to be any current in the chassis (0.6 V). I'd like also to know what can be done, is it something we can fix ourselves? Would a power supply from a laptop work for testing purposes, assuming it is the power supply? I'm in no mood to go through the return process, bought it at amazon.de. I'm using the stock 32V 5A power supply that came with it.

If AC power is present at the chassis and/or connectors with no other cables connected other than the power supply, it can only be the power supply.
The amplifier itself is only operated with DC voltage.

BUT this is not unusual. As long as the current flowing at the error voltage remains below 3.5mA, the whole thing is not dangerous, otherwise the existing FI switch in your fuse box should trigger. There is a high probability that it is not the only device in your household that generates an error voltage.
My AIYIMA original power supply (32V/5A) from the A07 generates an error voltage of 95.5 volts, power plug in the socket turned 180° 96.5 volts (choose plug direction with lower error voltage). That will be normal with this power supply.

A high-quality power supply, such as the Mean Well HRP-360-36 with a 3-pin power connection with protective earth, only generates approx. 9V AC voltage on the housing.

 

[Triliza]

12v power supply for opamps works as soon as mains is supplied, no need to turn on the switch

I don't have any other power supply to test, the one from the laptop doesn't fit, if it's a high probability that the amp power supply is the culprit I could buy another one.

 

[Triliza]

If AC power is present at the chassis and/or connectors with no other cables connected other than the power supply, it can only be the power supply.
The amplifier itself is only operated with DC voltage.

BUT this is not unusual. As long as the current flowing at the error voltage remains below 3.5mA, the whole thing is not dangerous, otherwise the existing FI switch in your fuse box should trigger. There is a high probability that it is not the only device in your household that generates an error voltage.
My AIYIMA original power supply (32V/5A) from the A07 generates an error voltage of 95.5 volts, power plug in the socket turned 180° 96.5 volts (choose plug direction with lower error voltage). That will be normal with this power supply.

A high-quality power supply, such as the Mean Well HRP-360-36 with a 3-pin power connection with protective earth, only generates approx. 9V AC voltage on the housing.

So what does all this mean, should I buy another power supply and the problem will go away, or has it something to do with my house power installation? My understanding of all power related is quite limited, so pardon the question if it's already explained above. What I get now when the amp is connected to the power socket but is off, is slightly above 9V. Something else I should try? Thanks.