AIYIMA A07 TPA3255 Review (Amplifier)

[Bruce Morgen]

Which shouldn't go much beyond the bundled power supply

I did exactly that -- running two of my A07s at 46VDC for literally years -- with not even a hint of a problem.

I'm just sayin'....

 

[hitechakias]

Having read about how good this amp is for the price I bought it from Amazon as an alternative for less electricity consumption (electricity charges in Greece went incredibly high) and it is... unlistenable to my frustration! It is too harsh in top end... even in low volumes...really fatiguing...never had such an issue before. What is going on? Is it common with this amp? When I find time I will measure with Umik to see which frequencies are responsible for the fatiguing sound. Rest of system: Kef R3 SPEAKERS, Loxjie D40 DAC, Technics sl-1210mk2 TURTABLE, Cambridge Audio CXC v2 CD PLAYER, WiiM Mini STREAMER, CABLES: QED Silver anniversary xt, QED Reference Optical, Qed Reference 40 RCA, Chord Clearway Coaxial.

 

[Bruce Morgen]

Is it common with this amp?

Obviously not or there would have been more comments like yours over the 22 months since the review was posted.

 

[diablo]

Having read about how good this amp is for the price I bought it from Amazon as an alternative for less electricity consumption (electricity charges in Greece went incredibly high) and it is... unlistenable to my frustration! It is too harsh in top end... even in low volumes...really fatiguing...never had such an issue before. What is going on? Is it common with this amp? When I find time I will measure with Umik to see which frequencies are responsible for the fatiguing sound. Rest of system: Kef R3 SPEAKERS, Loxjie D40 DAC, Technics sl-1210mk2 TURTABLE, Cambridge Audio CXC v2 CD PLAYER, WiiM Mini STREAMER, CABLES: QED Silver anniversary xt, QED Reference Optical, Qed Reference 40 RCA, Chord Clearway Coaxial.

I bought the Aiyima a few weeks ago and ran a simple test. I ran REW on my lounge speakers using my normal Yamaha R-N803D in Pure Direct mode. Then, leaving the Umik-1 and speakers in the same positions I simply swapped out that amp for the Aiyima.
The frequency response graphs were identical for the two amps. So I kept the A07 in place. Uses 4 watts instead of 34 with no signal.
Maybe your amp is faulty?

 

[staticV3]

it is... unlistenable to my frustration! It is too harsh in top end... even in low volumes...really fatiguing...never had such an issue before. What is going on?

The A07's frequency response is very dependent on the load you attach to it.
While it may be flat with simple resistive loads (like the ones Amir uses), a reactive load like a speaker can lead to a different response.

ASR member pma measured the A07's frequency response into reactive loads in this thread.

Tldr:
-JBL Control1 Pro:


-reactive dummy load:


That's most likely where the harshness that you're hearing comes from.

 

[Bruce Morgen]

The A07's frequency response is very dependent on the load you attach to it.
While it may be flat with simple resistive loads (like the ones Amir uses), a reactive load like a speaker can lead to a different response.

ASR member pma measured the A07's frequency response into reactive loads in this thread.

Tldr:
-JBL Control1 Pro:
View attachment 236931

-reactive dummy load:
View attachment 236932

That's most likely where the harshness that you're hearing comes from.

Those curves show nearly flat frequency response with a real world reactive load (an actual speaker) and a bright high end with PMA's so-called (and apparently highly) reactive dummy load, which apparently doesn't even remotely resemble the reactivity of a speaker. IOW, nothing about PMA's testing explains audible "harshness."

 

[hitechakias]

Having read about how good this amp is for the price I bought it from Amazon as an alternative for less electricity consumption (electricity charges in Greece went incredibly high) and it is... unlistenable to my frustration! It is too harsh in top end... even in low volumes...really fatiguing...never had such an issue before. What is going on? Is it common with this amp? When I find time I will measure with Umik to see which frequencies are responsible for the fatiguing sound. Rest of system: Kef R3 SPEAKERS, Loxjie D40 DAC, Technics sl-1210mk2 TURTABLE, Cambridge Audio CXC v2 CD PLAYER, WiiM Mini STREAMER, CABLES: QED Silver anniversary xt, QED Reference Optical, Qed Reference 40 RCA, Chord Clearway Coaxial.

That's the inroom frequency response.. where could the harshness come from?

 

[firestart3r]

Hello all,

I'm concerned about what Amir said in the review : "Personally I would not leave these plugged in permanently if I am not around."

From my understanding, Aiyima sells the amplifier without a power supply in Europe because it is not certified.

Is there a power supply that we know is certified and safe to use? I would like to leave the unit powered on all the time for simplicity reasons.

Again, my concern is safety and NOT how to get more watts.

Thanks

 

[Triliza]

Hello all,

I'm concerned about what Amir said in the review : "Personally I would not leave these plugged in permanently if I am not around."

From my understanding, Aiyima sells the amplifier without a power supply in Europe because it is not certified.

Is there a power supply that we know is certified and safe to use? I would like to leave the unit powered on all the time for simplicity reasons.

Again, my concern is safety and NOT how to get more watts.

Thanks

Amazon.de sell it with a power supply, I'd suppose is the one Aiyima provides. If you don't push the amp too hard I don't think something unsafe will happen, not any more than using any other electronic device I'd think, a lot of people are using this amp. But if you are concerned, buy an amp from Yamaha or such, if you can stretch a little your budget.

 

[diablo]

My A07, purchased from Amazon.uk came with the same power supply shown as supplied in Germany.

It has the CE marking. I'm hoping that the marking is genuine.

Mine gets unplugged at the end of the day, as I don't want even a slight chance of the house burning down. Though I'm a little concerned it will be damaged by that - as discussed earlier in this thread.

Would be nice to find a guaranteed safe PS that had some sort of soft start which could be unplugged - and didn't cost five times the price of the amp. Lol.

 

[firestart3r]

My A07, purchased from Amazon.uk came with the same power supply shown as supplied in Germany.
View attachment 237379
It has the CE marking. I'm hoping that the marking is genuine.

Mine gets unplugged at the end of the day, as I don't want even a slight chance of the house burning down. Though I'm a little concerned it will be damaged by that - as discussed earlier in this thread.

Would be nice to find a guaranteed safe PS that had some sort of soft start which could be unplugged - and didn't cost five times the price of the amp. Lol.

Totally agree with you!

Bought mine on amazon.ca and have the same power supply as you.

I found the Audiophonics 14749 but I'm not sure if it's certified or not. I don't see the CE logo on it...

The quest continues...

 

[peanuts2]

what exactly is the concern. is there a technical reason it should burn more than any other? is it because of low price?

 

[firestart3r]

what exactly is the concern. is there a technical reason it should burn more than any other? is it because of low price?

Amir tested the polarity and it was reversed.

Pretty sure it's not dangerous but he still mentioned that he wouldn't leave the device on at all times.

 

[somebodyelse]

what exactly is the concern. is there a technical reason it should burn more than any other? is it because of low price?

Uncertified stuff may or may not be built well. Corners may or may not have been cut to get the low price. With certification some external tester has done some testing on it to see that it meets the required standards for that certification. Some are more stringent than others.

Have a search for 3D printer PSUs catching fire - there's a reason people in a famously price sensitive market pay extra for a reputable PSU!

 

[Bruce Morgen]

Uncertified stuff may or may not be built well. Corners may or may not have been cut to get the low price. With certification some external tester has done some testing on it to see that it meets the required standards for that certification. Some are more stringent than others.

Have a search for 3D printer PSUs catching fire - there's a reason people in a famously price sensitive market pay extra for a reputable PSU!

As I understand it, a "CE" certification is a bit dodgy and just means the manufacturer states that the item meets the relevant safety standards required for sale in the EU and only applies to that manufacturer's designated application category. Good luck trying to get any but the most reputation-conscious Asian manufacturer to actually take responsibility if such an item causes injury or property damage in Poland or Denmark.

 

[somebodyelse]

As I understand it, a "CE" certification is a bit dodgy and just means the manufacturer states that the item meets the relevant safety standards required for sale in the EU and only applies to that manufacturer's designated application category. Good luck trying to get any but the most reputation-conscious Asian manufacturer to actually take responsibility if such an item causes injury or property damage in Poland or Denmark.

IIRC (and I may not...) CE can be self-certified, and it's the importer that's liable if it's not made in the EU. It's pretty much impossible to check up on. In contrast the FCC marking should be sufficient to check against the public database of test reports.

 

[pixelgarden]

Hi everyone. I have done most of the mods for the A07 i thought will give me most return.
I am currently using generic 24V 6 amp power supply and am very happy with the sound quality as of now. I hardly have to push the volume to 60% in windows before it gets too loud. A07 volume knob set at max.
Do you feel upgrading the power supply to Meanwell 36v 5 amp going to benefit me ? I mean strictly from a sound quality standpoint ? Bcoz i already have much headroom already on 24v SMPS. I don't want to upgrade if it's just for more headroom.

 

[Grooved]

My A07, purchased from Amazon.uk came with the same power supply shown as supplied in Germany.
View attachment 237379
It has the CE marking. I'm hoping that the marking is genuine.

Mine gets unplugged at the end of the day, as I don't want even a slight chance of the house burning down. Though I'm a little concerned it will be damaged by that - as discussed earlier in this thread.

Would be nice to find a guaranteed safe PS that had some sort of soft start which could be unplugged - and didn't cost five times the price of the amp. Lol.

Hi,

first, even if it doesn't mean that the specs are not right, this CE logo is totally a fake one, the real one has more space between both letters, if the C was a full O, it would just cover the left part of the E:

Second, it's not really a certification, it's more that you are supposed to put this mark only if you have done a conformity assessment before...
Original text:
"Manufacturers... It is their responsibility to carry out the conformity assessment, set up the technical file, issue the EU declaration of conformity and affix the CE marking to a product."

 

[peanuts2]

it seems chinese export is a myth.

"However, the European Commission says that this is a misconception.[18] The matter was raised at the European Parliament in 2008.[21] The Commission responded that it was unaware of the existence of any "Chinese Export" mark and that, in its view, the misunderstanding had arisen because a producer had failed to respect the precise dimensions and proportions of the mark as prescribed in the legislation.[18] The Commission was also aware of fraudulent misuse of the mark on products that did not comply with the standards, but that this is a separate issue..."

CE marking - Wikipedia

en.wikipedia.org

 

[trungdtmc]

I has just replace stock heatsink by another bigger. Now it really cooler than before