AIYIMA A07 TPA3255 Review (Amplifier)

[Toku]

So you say it gets less hot than the A07? It looks like the internals are pretty much the same as the A07, also the size of the heatsink . What if the connection between the chip and the heatsink is not as good, so that the heat doesn't get transported to the heatsink as well? Or is this not possible because the case would get just as hot?

To answer your question, I arranged A07 with A04/TPA3255 for several hours in an environment with a room temperature of 20 degrees and observed the temperature change. Both are connected to the same 36V power supply.
As a result, both models generate less heat under these conditions, but the temperature of A07, which has a large case, is slightly lower than that of A04/TPA3255.

 

[Ralferator]

To answer your question, I arranged A07 with A04/TPA3255 for several hours in an environment with a room temperature of 20 degrees and observed the temperature change. Both are connected to the same 36V power supply.
As a result, both models generate less heat under these conditions, but the temperature of A07, which has a large case, is slightly lower than that of A04/TPA3255.

Thank you. So at 36V they are all not getting very hot.

 

[Toku]

Thank you. So at 36V they are all not getting very hot.

I have used A07 at 48V for a while before. But in the hot summer season in Japan, the case gets too hot and I can't rest assured.
There are many other TPA3255 products, but I use them at about 40V or less.

 

[IowAudio]

Cool. There are the Topping MX3 & Loxjie A30, but for someone who just wants an analog speaker amp, it’s a good budget option.

Except the Topping MX3 scored quite poorly. If this SINAD bisiness matters I wouldn't want one...

 

[MZKM]

Except the Topping MX3 scored quite poorly. If this SINAD bisiness matters I wouldn't want one...

Well, like I said, this is a better amp, the Topping is for people that need digital connection, Bluetooth, sub out, and a remote, all for <$150.

 

[Xulonn]

[Cross-posted from Amir's YouTube video about this review]

Hidden gem, indeed!

[edit] I noticed that three pictures of this amplifier show different sizes of heat sink, with the original unit that Amir tested being the smallest.

I don't own the Aiyima A07, but early last year I purchased their lower-power A04 amp (TPA3251) for a "portable" system that I use with a 12v Talentcell 38400mAh Li-ion battery pack. I purchased both from Amazon last year. Before the pandemic hit, I took my "portable" system with a (DAP, amp, tiny Yamaha speakers and battery pack) to the weekly local (Boquete, Chiriqui, Panama) food, arts and crafts market where I used to sell my artisan woodturnings.

The quality and performance of the Aiyima A04 is very good, and would expect the more powerful A07 to probably equal the performance of my Ghent/ICEPower 70w amplification in my main system.

The Aiyima A07 was not currently found via my search at Amazon, but the AiyimaAudio store on AliExpress has it for USD $50.62 with free shipping to the US from China, or from a German location to Germany for free. Better hurry, though - AliExpress shows 80 sold and only 66 pieces available! (Another AliExpress page shows 726 available.)

 

[escape2]

I'm guessing the AliExpress listing does not include power supply?

 

[Bruce Morgen]

I'm guessing the AliExpress listing does not include power supply?

Yes -- AFAICT A07s with bundled power bricks are the exception pretty much everywhere other than Amazon.

 

[DKSH]

I'm looking to purchase but I see two options. Can anyone advise me on the differences between these two version?

 

[IowAudio]

Can't find one anywhere but AliExpress. Oh well may just try the Aiyima A04.

 

[phoenixsong]

I'm looking to purchase but I see two options. Can anyone advise me on the differences between these two version?

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They are stated to use different op amps

 

[infinitesymphony]

I'm looking to purchase but I see two options. Can anyone advise me on the differences between these two version?

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@pma tested this a while back and found that the LM4562 offered a slight improvement. Nice of Aiyima to provide that option now.

 

[pma]

https://www.audiosciencereview.com/...-measurements-and-review-lm4562-option.19155/

 

[infinitesymphony]

@pma, maybe you can answer this -- how do you feel about this amp from a safety perspective?

 

[pma]

@pma, maybe you can answer this -- how do you feel about this amp from a safety perspective?

I am not sure what you mean. In case you mean reliability, then I would repeat what I already said. I do not think it is a good idea to operate this amp from 48Vdc power supply at higher output power for longer period of time. Because of too small heatsink inside and no vents, the heatsink and chip temperature rises quickly (I provided measurements). Even if there is a thermal protection, high temperature always reduces life time of electronic components. So to be on safe side re heat and long life time, I would stick with 32 - 36V power supply. The power is still satisfying then.

 

[infinitesymphony]

I am not sure what you mean. In case you mean reliability, then I would repeat what I already said. I do not think it is a good idea to operate this amp from 48Vdc power supply at higher output power for longer period of time. Because of too small heatsink inside and no vents, the heatsink and chip temperature rises quickly (I provided measurements). Even if there is a thermal protection, high temperature always reduces life time of electronic components. So to be on safe side re heat and long life time, I would stick with 32 - 36V power supply. The power is still satisfying then.

That's good info, the summary is appreciated. I guess I'm thinking about it from the perspective of speaker safety after learning about what can go wrong from a protection standpoint (ex. Topping L30 headphone amp).

 

[pma]

I guess I'm thinking about it from the perspective of speaker safety after learning about what can go wrong from a protection standpoint

This is a tiny amplifier and there is no place inside left. In case of "serious", big power amplifiers, we put an extra DC protection or DC protection board inside. It may be based on power relay (however this will deteriorate with time) or a good solid state relay ( we have good power mosfets nowadays). DC failure is the biggest killer of expensive woofers, so we monitor output DC for level and time duration and if it goes unsafe, the protection board switches off the speaker output. I know the chip has embedded protection, but in case of serious failure and melted chip you never know.

 

[Bruce Morgen]

This is a tiny amplifier and there is no place inside left. In case of "serious", big power amplifiers, we put an extra DC protection or DC protection board inside. It may be based on power relay (however this will deteriorate with time) or a good solid state relay ( we have good power mosfets nowadays). DC failure is the biggest killer of expensive woofers, so we monitor output DC for level and time duration and if it goes unsafe, the protection board switches off the speaker output. I know the chip has embedded protection, but in case of serious failure and melted chip you never know.

It would be good to see some comparable-wattage/load temperature readings for 36 vs. 48 volt PSUs. My guess? Little or no difference. There's a reason space heaters are rated in watts and not volts or amps, and AFAICT the same principle applies.

 

[Bruce Morgen]

This is a tiny amplifier and there is no place inside left.

There's some room on the right between the edge of the PCB and the side of the case. Taking advantage of that space with a big, "T"-shaped heat sink would be helpful, but that would be a bespoke item and would undoubtedly bust Aiyima's manufacturing budget for such a low-cost product.

 

[Jdunk54nl]

Or just take a drill and drill some cooling hole vents into top and bottom.
Or take a dremel and a grinding wheel and make some long slots for venting.
Either one of those would take less than 10 minutes and the amp would probably cool quite a bit better. It is just slid into a groove on the bottom plate IIRC so nothing to worry about by making those holes (Please remove the amp prior to drilling, don't drill through it on accident, I mean no mounting issues to worry about)

Or not worry about it as it isn't a real issue unless you are REALLY pushing this amp.