AIYIMA A07 TPA3255 Review (Amplifier)

[Deleted member 46664]

Certainly am.

Okay ... I recently ran across a problem with my own A07 when I decided to test this "opamp rolling" thing... (Yeah I know...)

In the end, I discovered I had a bad socket under one of the chips. I also ran across a number of articles about fake 5532s. I'm not saying you have the same problem but it might be worth checking that the two opamp chips are properly seated in their sockets. Which chip you have in there doesn't make a whole lot of difference but a bad connection will ... I replaced the sockets and then installed 4558 chips out of my personal stock. Happy as a clam now...

 

[Loathecliff]

^ Thxs Douglas. Yes I saw your post on op amps.
It has a case seal on one side otherwise the top would have been off by now.
I did consider tilting the lid..... too risky, I'd be wanting to see both sides of the board.

I tried to convince myself for two days but the lack of subtlety finally got to me.
With various amps in the collection I tried our bottom line, a fine example of the glorious Acoustic Solutions sp101!
(In a lengthy (many amp) DBT years ago it came out third from bottom, and better than a WhatHiFi top choice with Cambridge Audio written on it!....some audio revenge moments can be sweet).
- Last Friday it wasn't quite as 'interfering' as the Aiyima. That was not a good sign.

This is the purchase route. Supposedly from Aiyma, and in a convincing box, but who knows for sure? https://www.amazon.es/AIYIMA-A07-Es...1_2?keywords=Aiyima+a07&qid=1650775892&sr=8-2

 

[Loathecliff]

Update.
So I tried again with the A07 this time with a 19v PS, and guess what, all the grain has gone
Went back to the supplied PS, and it's still fine.
Happy to own up to being an aging idiot. Then Mrs L. walks in.
She does not know which amp is in use. I asked her to listen to a little of her favourite concerto (Hadyn) again.
"Is that better than the amp from yesterday? " I asked.
"It's gorgeous. That other thing was almost screeching on violins" she said.
Then I tell it's the same amp.
Neither of us understand what could have changed.
What am I missing?

Edit:- DB's chip socket. Could well be. Bounced around in the post. Dropped from a great height

 

[Deleted member 46664]

Update.
So I tried again with the A07 this time with a 19v PS, and guess what, all the grain has gone
Went back to the supplied PS, and it's still fine.
Happy to own up to being an aging idiot. Then Mrs L. walks in.
She does not know which amp is in use. I asked her to listen to a little of her favourite concerto (Hadyn) again.
"Is that better than the amp from yesterday? " I asked.
"It's gorgeous. That other thing was almost screeching on violins" she said.
Then I tell it's the same amp.
Neither of us understand what could have changed.
What am I missing?

Do you have any idea how much our hearing varies from day to day ... temperature, humidity, blood pressure, mood, expectation, indigestion, the neighbour's cat screeching from the top of their ugly red fence.... all affect the way things sound to us. Yesterday was one of those "everything's an emergency" days and by the time I sat down to unwind with a little Dire Straights... everything sounded like crap. So this morning I put the same playlist back on and it sounds great... nothing changed... except my hearing/mood.

But just to play it safe ... check your connections... maybe clean the plugs...

 

[Loathecliff]

Do you have any idea how much our hearing varies from day to day ..

Indeed I do Douglas, but I swapped amps to a 3116 and all was fine.
Plus Mrs. L also thought the A07 was rubbish.
I might ask Amazon if I can look within (at the socket) as there is a problem.

Re plugs. Neighbour gave me a box of NGKs as they don't fit the Ferrari engine in his Maserati (sic).
Quality every time here!

 

[Deleted member 46664]

Indeed I do Douglas, but I swapped amps to a 3116 and all was fine.
Plus Mrs. L also thought the A07 was rubbish.
I might ask Amazon if I can look within (at the socket) as there is a problem.

Amazon does not control the warranty .. Aiyima does.
And I don't see any problem popping the top since they actually advertised changing the chips at one time.

Re plugs. Neighbour gave me a box of NGKs as they don't fit the Ferrari engine in his Maserati (sic).
Quality every time here!

LOL ... it's an amplifier ... I meant the RCA and power plugs... But you can feel free to take it racing if you like.

 

[mightycicadalord]

Do you have any idea how much our hearing varies from day to day ... temperature, humidity, blood pressure, mood, expectation, indigestion, the neighbour's cat screeching from the top of their ugly red fence.... all affect the way things sound to us. Yesterday was one of those "everything's an emergency" days and by the time I sat down to unwind with a little Dire Straights... everything sounded like crap. So this morning I put the same playlist back on and it sounds great... nothing changed... except my hearing/mood.

But just to play it safe ... check your connections... maybe clean the plugs...

I think people super underestimate how great the swing is on this. As you describe, one day your system is the worst sounding thing in the world, the next it sounds like butter.

 

[Deleted member 46664]

I think people super underestimate how great the swing is on this. As you describe, one day your system is the worst sounding thing in the world, the next it sounds like butter.

yep ... Going back to Dire Straights for a moment: "Sometimes you're the windshield. Sometimes you're the bug".

 

[Loathecliff]

Amazon does not control the warranty .. Aiyima does.

True, but as this is Amazon fulfilled I want this logged because of who does the return inspections.
But Thxs for the op amp swap reminder. I will contact Aiyima too.

 

[RandomEar]

Got an A07 yesterday as a temporary solution. Quick impressions:

• It's tiny. The pictures really misled me: It's only about half the size of my DAC (SU-9n). About 15 x 10 x 4 cm.
• My speaker cables are trying to pull it off the shelf
  
• It looks and feels cheap. I get it, it's an amp for 80$. The volume knob is scratchy, there are some small scuffs on the housing of my unit, some of the feet fell off/didn't really stick, the 32 V PSU which came with it looks "barely trustworthy".
• The PSU emits a faint noise around 7 kHz when plugged in, which is audible up to 0.5 m away. Not really of any concern, as it's inaudible where it usually sits (e.g. behind a shelf).
• There's no speaker pop when turning on the amp. Was kinda impressed considering the price.
• There's some speaker hiss. In a quiet environment, it's audible up to about 2 m with my ELACs (sensitivity 87 dB) with the volume set to 5/60 on the amp. In an unfair comparison, on a Hypex NC122MP-based amp, speaker hiss is only audible up to around 0.2 m.
• The speaker hiss scales with the volume setting.
• Overall, the A07 works and sounds fine. There's really nothing special about it and nothing to complain about.
• My subjective impression is, that there's something up with the treble. Might be placebo, because I stumbled upon the measurements by @pma here, before I got the Aiyima. There seems to be a very faint lack of higher frequencies (>7 kHz). Can't really put my finger on it and it's probably imagination. I'm sorry that I can't provide any measurements for this. Nonetheless, it should be clear that this amp isn't as perfectly corrected as a Purifi unit for 20x the money.

Not sure if I'm going to keep this, even as a temp solution. Just want to get rid of that speaker hiss for now and this certainly doesn't achieve that, although it is better than my current setup. Also, the fact that I'd essentially have to glue it down to keep it in place doesn't really work in its favour

 

[Loathecliff]

the fact that I'd essentially have to glue it down to keep it in place doesn't really work in its favour

Ideas:-
1) Put a brick on top.
2) Stick it inside a broken Krell amp.
3)?

 

[NewbieAudiophileExpert]

I have a Fosi Audio BT20A-S and i quite like it - has anybody here used both the Fosi and Aiyima A07? Curious to know if it's a worthwhile purchase at this point in time?

 

[Raindog123]

Just want to get rid of that speaker hiss for now and this certainly doesn't achieve that, although it is better than my current setup.

Maybe the source of this hiss is elsewhere? Just to consider: (a) many of us have zero such hiss, and (b) you also get “it in your current setup“… - Look for some RF pickup by a cable before the amp and/or play with [cabling] ground loops.

 

[Deleted member 46664]

Got an A07 yesterday as a temporary solution. Quick impressions:

• It's tiny. The pictures really misled me: It's only about half the size of my DAC (SU-9n). About 15 x 10 x 4 cm.
• My speaker cables are trying to pull it off the shelf
  
• It looks and feels cheap. I get it, it's an amp for 80$. The volume knob is scratchy, there are some small scuffs on the housing of my unit, some of the feet fell off/didn't really stick, the 32 V PSU which came with it looks "barely trustworthy".
• The PSU emits a faint noise around 7 kHz when plugged in, which is audible up to 0.5 m away. Not really of any concern, as it's inaudible where it usually sits (e.g. behind a shelf).
• There's no speaker pop when turning on the amp. Was kinda impressed considering the price.
• There's some speaker hiss. In a quiet environment, it's audible up to about 2 m with my ELACs (sensitivity 87 dB) with the volume set to 5/60 on the amp. In an unfair comparison, on a Hypex NC122MP-based amp, speaker hiss is only audible up to around 0.2 m.
• The speaker hiss scales with the volume setting.
• Overall, the A07 works and sounds fine. There's really nothing special about it and nothing to complain about.
• My subjective impression is, that there's something up with the treble. Might be placebo, because I stumbled upon the measurements by @pma here, before I got the Aiyima. There seems to be a very faint lack of higher frequencies (>7 kHz). Can't really put my finger on it and it's probably imagination. I'm sorry that I can't provide any measurements for this. Nonetheless, it should be clear that this amp isn't as perfectly corrected as a Purifi unit for 20x the money.

Not sure if I'm going to keep this, even as a temp solution. Just want to get rid of that speaker hiss for now and this certainly doesn't achieve that, although it is better than my current setup. Also, the fact that I'd essentially have to glue it down to keep it in place doesn't really work in its favour

From your description I would guess you've gotten a return/repack. Mine has none of those issues. I did have a problem with one of the op-amp sockets, but that was an easy fix, so no return (for all I know I may have actually caused the problem trial-flipping the chips).

The 32v supply that comes with the A07 should be totally silent, even with your ear against the casing. So that may also be a return/repack item. This supply is the best compromise for power, temperature and longivity with Aiyima's configuration of the TPA3255 chip. You can try higher voltages but you would likely run into thermal shutdowns if you push it too hard.

I suggest returning it in exchange for another one .... second times the charm?

 

[Deleted member 46664]

I have a Fosi Audio BT20A-S and i quite like it - has anybody here used both the Fosi and Aiyima A07? Curious to know if it's a worthwhile purchase at this point in time?

The Fosi is based on the TPA3116 chip. The Aiyima will be much happier on lower impedance speakers than the Fosi... if you have 8 ohm speakers the only difference will be power... about 35w/ch for the Fosi and 60w/ch for the Aiyima.

 

[RandomEar]

Maybe the source of this hiss is elsewhere? Just to consider: (a) many of us have zero such hiss, and (b) you also get “it in your current setup“… - Look for some RF pickup by a cable before the amp and/or play with [cabling] ground loops.

Speaker hiss was nearly imperceptible with an Audiophonics MPA-S125NC XLR, therefore I don't think that is the case. Also, it sounds pink noise-ish, which is why I don't think it is related to a ground loop. It sounds to me like the noise floor of the amp and the levels correlate well with measured THD+N at low powers (0.1 W or below, noise-dominated). I'm not saying anything else is excluded, but my working theory is "it's the amp".

From your description I would guess you've gotten a return/repack. Mine has none of those issues. I did have a problem with one of the op-amp sockets, but that was an easy fix, so no return (for all I know I may have actually caused the problem trial-flipping the chips).

The 32v supply that comes with the A07 should be totally silent, even with your ear against the casing. So that may also be a return/repack item. This supply is the best compromise for power, temperature and longivity with Aiyima's configuration of the TPA3255 chip. You can try higher voltages but you would likely run into thermal shutdowns if you push it too hard.

I suggest returning it in exchange for another one .... second times the charm?

It looks like a repack, yeah. With the PSU's, it's a hit and miss: Your unit might be silent, mine might not be. It also depends on what other devices are present in the local circuit. PC's and some LED bulbs can leak EMF back into the power line, which might be causing the issues in my unit. But it's not that big of a deal, as I wrote - inaudible from behind the shelf.

 

[Deleted member 46664]

It looks like a repack, yeah. With the PSU's, it's a hit and miss: Your unit might be silent, mine might not be. It also depends on what other devices are present in the local circuit. PC's and some LED bulbs can leak EMF back into the power line, which might be causing the issues in my unit. But it's not that big of a deal, as I wrote - inaudible from behind the shelf.

IF you do an exchange, you will get a different PSU as well ... so that might also be the end of that problem.
Usually a high pitched whistle from a SMPS indicates either a faulty transformer or a problem with the chopper circuit.

One thing to keep in mind is that with the large inrush of current when AC is first connected, it is generally best to leave these amps and bricks connected and powered up all the time. The on-off switch on the front does not switch the bulk supply off... it merely puts the 3255 into it's Reset state where the outputs are off and the rest is in a sleep mode. For the end user it's as good as off... but all the big caps are kept fully charged. Repeatedly powering it completely down means that the brick will have to cope with huge inrushes every time you turn it back on... and with the big caps in these amplifiers that will eventually cause the brick to fail.

 

[RandomEar]

IF you do an exchange, you will get a different PSU as well ... so that might also be the end of that problem.
Usually a high pitched whistle from a SMPS indicates either a faulty transformer or a problem with the chopper circuit.

One thing to keep in mind is that with the large inrush of current when AC is first connected, it is generally best to leave these amps and bricks connected and powered up all the time. The on-off switch on the front does not switch the bulk supply off... it merely puts the 3255 into it's Reset state where the outputs are off and the rest is in a sleep mode. For the end user it's as good as off... but all the big caps are kept fully charged. Repeatedly powering it completely down means that the brick will have to cope with huge inrushes every time you turn it back on... and with the big caps in these amplifiers that will eventually cause the brick to fail.

I don't disagree. But for power saving reasons and to reduce the risk of smoky surprises in my sleep, I disconnect my setup from the wall over night. The PSU is either designed well and lives on, or it fails at some point and I get a (better) replacement. I have not yet had any SMPS die on me, so I'm somewhat hopeful concerning their life expectancy

Different topic: My cheapo power meter says, that the Aiyima A07 consumes

• 4 W for some seconds when plugged in, 0 W after a bout a minute with the PSU connected but the amp turned off
• 7 W with the amp turned on but nothing playing
• 7 W with music playing at background listening levels (around 55 dB peak on uncalibrated Noise Meter app) in a near field application with 87 dB speakers
• 7 W at elevated levels (around 75 dB peak) in the same application

I don't tend to trust that power meter below 10 W, but the difference (amp off vs. amp on) looks plausible. And at those listening levels, the sound power in my setup should be below 0.1 W, so it makes sense that the consumption appears unchanged. The actual difference isn't zero, but my meter doesn't resolve well enough to show it.

 

[staticV3]

In case your meter can calculate power consumption in Wh per day/week/year, you could set it to that, let it collect data for a bit, then convert that back to W.
That's what I'm doing to squeeze a bit more resolution out of my meter

 

[Deleted member 46664]

I don't disagree. But for power saving reasons and to reduce the risk of smoky surprises in my sleep, I disconnect my setup from the wall over night. The PSU is either designed well and lives on, or it fails at some point and I get a (better) replacement. I have not yet had any SMPS die on me, so I'm somewhat hopeful concerning their life expectancy

The best I can tell you is that while working as a service technician, the most frequent cause of a dead "brick" was that it was being constantly plugged in and unplugged. Those bricks had an average of about a year or two lifetime, where the ones that have been left running day and night for years tended to last longer.

I've got a couple here that have been running for more than 10 years.

There is even some evidence of this right on this forum ...

SMPS supplies are rubbish

8x24" LG LED monitors used in our offices. 4 of them on a single computer (quad screens) used 4-5 hours a day, the other 2 in 2 pairs on other PCs that see 1-2 hours per day. 12 months old approx. They started failing 6 months in and now 5 out of 8 PSUs have died. We are only talking 23-32 Watt...

www.audiosciencereview.com

I agree with the others saying "If these were correctly designed...", except they weren't. Most of the bricks are generic supplies rebranded on contracts with the amplifier companies. They're not designed for this application at all.

You are, of course, free to make your own decisions... I'm just trying to provide information.

Different topic: My cheapo power meter says, that the Aiyima A07 consumes

• 4 W for some seconds when plugged in, 0 W after a bout a minute with the PSU connected but the amp turned off

The initial surge, which lasts just a fraction of a second can peak at 10 to 11 amps... that's where the problem lies.