AIYIMA A07 TPA3255 Review (Amplifier)

[Guddu]

I'm not sure why someone would now buy this over the A07MAX amp - I guess, just for volume, with the log pot rather than the taper on the MAX?

probably option to go mono.

 

[IceLord]

Info about the changes and new features here (better internal components, pre-out controlled by volume, better heat dissipation,... seems a good upgrade):

Looking forward to see an @amirm review soon...

 

[Bruce Morgen]

Info about the changes and new features here (better internal components, pre-out controlled by volume, better heat dissipation,... seems a good upgrade):

Looking forward to see an @amirm review soon...

No significant advantage in my particular use case, but certainly better in a typical 2.1 setup or for when the amp is pushed hard for long periods. The major disappointment is the absence of PFFB.

 

[-Jim-]

I too appreciate the evolution of the A07. My, "now old" A07 is used for a set of Rear Atmos Speakers which don't get a lot of use, but when called upon works just fine.

The new certainly moves the bar a bit but like @Bruce Morgen they need to address PFFB before it becomes a solid choice for say a 2.1 near field desk setup. (IMHO) However, I'm really impressed how far Aiyima & Fosi have come based on Customer feedback.

 

[IceLord]

If we take into account the price....adding such things like PFFB or XLR inputs and 12V trigger, makes no sense IMHO...what would be the market positioning against the A70??

The movement seems very valid for me as long as it pretends to increase the lifecycle of an entry level amplifier that has been a disrupting product but needs an upgrade to continue being competitive (in a very competitive market).

Good job from my point of view @AIYIMA .

PD: what still is a lack in the Aiyima ecosystem is a good family look&feel for a set of products that could be used together (by the moment every new model is like apples and pears from each other). Now that you have a good line of products....When will you mind about a good family look&feel?? [DAC/PRE-AMP]+[AMP]+[SUB-AMP].

 

[Bruce Morgen]

My, "now old" A07 is used for a set of Rear Atmos Speakers which don't get a lot of use, but when called upon works just fine.

My two elderly (the ones with the 50WVDC shunt capacitors) A07s drive the four ambience/surround speakers in my 7.1 system. Since they get their input via a DSP unit -- mostly to EQ the speakers -- I could easily compensate for the load impedance dependency that PFFB remedies.

 

[Bruce Morgen]

If we take into account the price....adding such things like PFFB or XLR inputs and 12V trigger, makes no sense IMHO...what would be the market positioning against the A70??

I separate (relatively straightforward?) performance upgrades like PFFB from feature updates like "XLR inputs and 12V trigger" -- YMMV and clearly does.

 

[Mistletoe]

I'm really excited to see the A07 Premium. Hope to try one out soon. Looks like they have listened to the feedback and made it even better. I think it looks a lot nicer too. I'd love to see some new testing of it!

 

[Scrivs]

Yawn

 

[xschop]

If the A07 Premium came with PFFB, I'd buy one. It looks like the same physical size case body and PCB as the original.

 

[Jimster480]

Does this have auto off and on?

 

[PMB]

This is a review and detailed measurements of the AIYIMA A07 desktop amplifier based on TPA3255 class D amplifier chip. It was kindly purchased new by a member and drop shipped to me. The cost is US $72 on Amazon including prime shipping. And as of this shipping, it also included a 32 volt, 5 amp switching power supply. Member also purchased and sent me a 48 volt/3 amp power supply which I also tested.

The case is standard budget audio affair:
View attachment 102785

The volume control feels cheep but does the job. The back panel terminals were way too small for my binding posts:

View attachment 102786

The DC input socket was quite stiff especially with the 48 volt power supply. Tightness is not a bad thing as far as power transfer is concerned but this was a bit too stiff. Here are the two power supplies:

View attachment 102787

They both feel kind of cheap as they would be at these prices ($21 for the 48 volt one). Personally I would not leave these plugged in permanently if I am not around. The included power supply has a two-pronged AC cable that was not polarized. Rotating it around made a small difference in mains leakage.

AIYIMA A07 Measurements
Let's start with our usual dashboard of 5 watts into 4 ohms:
View attachment 102788

As you see in the FFT display, there is considerable amount of mains leakage at 60 Hz. This tends to be a function of switching power supplies. I played with grounding and improved it a lot in one channel but not in the other (not shown). SINAD did not get impacted since it is bound by distortion harmonics. As it is, performance is above average:
View attachment 102789

Signal to noise ratio is not great due to the mains hum:
View attachment 102790

Frequency response is well behaved, albeit with a slight droop at 20 kHz:

View attachment 102791

Crosstalk is good and well above bargain basement desktop amps:
View attachment 102792

Power is everything in a small amp so let's see how we do with 4 ohm load:

View attachment 102793

As expected, with low impedance of 4 ohm we are current limited so the 5 amp stock power supply does better, turning in 77 watts. Yes, the 300 watt rating is a fantasy but maybe it can do better with momentary peaks. Alas, its aggressive protection circuit would shut it down and not let me test max and peak power.

Naturally the higher voltage power supply does better with 8 ohm load where we become voltage limited:
View attachment 102794

Sweeping power vs frequency and distortion shows a very well behaved class D amplifier:
View attachment 102795

Conclusions
Traditionally these desktop amplifiers have produced really poor performance in the form of noise and distortion. Not so anymore. These TPA3255 based amps seem to have good bones in them, producing above average performance for peanuts. Alas, you are saddled with two boxes and cheap and potentially non-safety compliant parts. For desktop use, these are probably acceptable compromises.

I am going to recommend the AIYIMA A07 based on its performance.

And with this, our last review of 2020 comes to an end! Nice that it is ending on a happy note.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Your test is based on 32V 5A/48V 3A. The test result of 77W/55W and not reaching 300W*2 (it is actually 280W*2) as it is claimed to have. It raises a question if the test is a fail or if the amp is broken. That said there are big differences in performance. 48V 10A that is available should give more relatable test results. But because these are for 24V to 48V power it still gives a good idea what the power does and what power to pair with your speakers. That said 48V 3A that you have there is piss weak for this amp. That explains the 55W poor result for 4 Ohm. Nominal for the A07 with 48V 10A is about 200W*2 and peak 280W*2. To be honest I think these numbers are still optimistic. Nominal 170W*2 and peak 250W*2 most likely would be closer with 48V 10A power. I've seen numbers like 48V 12A associated with these amps.

 

[PMB]

If the A07 Premium came with PFFB, I'd buy one. It looks like the same physical size case body and PCB as the original.

Beefier capacitors that give fuller sound for my opinion is better than A07 Max, A70, A80 for example. Plus the Premium 3.5mm output for example active sub is controlled from the master volume. Cooling is by heatsink screwed to the case using the case itself for heat expansion.

 

[Bruce Morgen]

Your test is based on 32V 5A/48V 3A. The test result of 77W/55W and not reaching 300W*2 (it is actually 280W*2) as it is claimed to have. It raises a question if the test is a fail or if the amp is broken. That said there are big differences in performance. 48V 10A that is available should give more relatable test results. But because these are for 24V to 48V power it still gives a good idea what the power does and what power to pair with your speakers. That said 48V 3A that you have there is piss weak for this amp. That explains the 55W poor result for 4 Ohm. Nominal for the A07 with 48V 10A is about 200W*2 and peak 280W*2. To be honest I think these numbers are still optimistic. Nominal 170W*2 and peak 250W*2 most likely would be closer with 48V 10A power. I've seen numbers like 48V 12A associated with these amps.

These things have been around for 6+ years, so their limitations are quite well known by now, as is the tendency of the manufacturers of gear in this price range to publish overoptimistic specs based on the TI datasheet. Although the sort of numbers you mention are marginally within the realm of possibility for the TPA3255 chip itself, pushing the output of this particular amp very far into three-digit WPC territory is inadvisable due to its thermal shortcomings and would likely result in the chip's built-in thermal protection shutting it down. The key here is "know thy use case" -- when it comes to desktop/nearfield applications, a "test result of 77W/55W" is going to be perfectly adequate (depending on speaker sensitivity and nominal impedance of course), and if you find yourself consistently requiring much more power than that, well then, this amp is probably not for you.

 

[Bruce Morgen]

Beefier capacitors that give fuller sound

Easily added without modifying the A07 -- you can do that anywhere along the PSU-to-amp cable by simply adding more capacitance in shunt. I wired a 3300 mFd electrolytic right to the barrier strip of the industrial SMPS I use to with my two A07s -- it doesn't do much of anything in my application AFAICT, but every use case is different and YMMV.

 

[PMB]

These things have been around for 6+ years, so their limitations are quite well known by now, as is the tendency of the manufacturers of gear in this price range to publish overoptimistic specs based on the TI datasheet. Although the sort of numbers you mention are marginally within the realm of possibility for the TPA3255 chip itself, pushing the output of this particular amp very far into three-digit WPC territory is inadvisable due to its thermal shortcomings and would likely result in the chip's built-in thermal protection shutting it down. The key here is "know thy use case" -- when it comes to desktop/nearfield applications, a "test result of 77W/55W" is going to be perfectly adequate (depending on speaker sensitivity and nominal impedance of course), and if you find yourself consistently requiring much more power than that, well then, this amp is probably not for you.

I bought the revised A07 Premium (48V 10A) that has beefed up capacitors and uses the case as it cooling for the TPA3255. My system has Magnat Vector Needle speakers with Active Magnat Alpha A30 sub. Sound comparison of course is a taste issue but I put the A07 Premium ahead of amps A70, A80, A20 and A07 Max. These cost lot more coin but to me having leaner capacitors can't open these amps up like the A07 Premium does. Not even the lme49720 that A20 has an improved op amp in my opinion does justice. Lot more connectivity options but that's all. Single Ended input is enough and 3.5mm output that is controlled from the master volume of the A07 Premium is all you need.

 

[Bruce Morgen]

I bought the revised A07 Premium (48V 10A) that has beefed up capacitors and uses the case as it cooling for the TPA3255. My system has Magnat Vector Needle speakers with Active Magnat Alpha A30 sub. Sound comparison of course is a taste issue but I put the A07 Premium ahead of amps A70, A80, A20 and A07 Max. These cost lot more coin but to me having leaner capacitors can't open these amps up like the A07 Premium does. Not even the lme49720 that A20 has an improved op amp in my opinion does justice. Lot more connectivity options but that's all. Single Ended input is enough and 3.5mm output that is controlled from the master volume of the A07 Premium is all you need.

This is an A07 review thread -- you have wandered way off-topic. By and large, we are well aware that there are better TPA3255 implementations available than that now-elderly design.

 

[PMB]

This is an A07 review thread -- you have wandered way off-topic. By and large, we are well aware that there are better TPA3255 implementations available than that now-elderly design.

Same design with better components and cooling. It is a comparison that many in this thread are doing or asking. Absolutely relevant to point the differences in power and components used.

 

[PMB]

FYI: There is a version of this amp called A07 Premium. My apologies if it has been posted on ASR already. The Premium uses the case as the heatsink. My preliminary impression is that it sounds the same as my FOSI ZA3, runs as cool and is also a bit smaller. AIYIMA A07 Premium

All of these amps with tpa3255+NE5532P*2 combination sound very close. FOSI ZA3 on Single Ended on paper looks very close. Of course there are Balanced and sub that explains the cost of double the coin. If you are happy with Single Ended only the A07 Premium is a great choice. To me it sounds better than A07 Max, A70, A20 for example.

 

[Bruce Morgen]

All of these amps with tpa3255+NE5532P*2 combination sound very close. FOSI ZA3 on Single Ended on paper looks very close. Of course there are Balanced and sub that explains the cost of double the coin. If you are happy with Single Ended only the A07 Premium is a great choice. To me it sounds better than A07 Max, A70, A20 for example.

Yeah, I understood that opinion the first time you stated it and I agree that the output chip and the op-amps pretty much define the performance of "All those amps...". IMO and FWIW, the question is: "For any particular use case, are those admittedly small differences you claim to hear significant enough for serious consideration?". In my case, no -- but YMMV and apparently does. Fair enough...