AIYIMA A07 TPA3255 Review (Amplifier)

[DuncanTodd]

Just going by the specs -- and its likely decent quality notwithstanding -- this thing will not unlock the A07's potential, not even close. Aiyima's recommendation of a 48VDC 7.5A SMPS is at the lower edge of what it takes to unleash that potential.

This is what powers the A07 that drives my main L+R speakers -- I got mine for $25 USD via eBay. I like its voltage adjustment knob, LED voltage display, and thermostatically-controlled fan -- but those are "bells & whistles" and virtually any unit with similar specs will do. You'll need to do a little DIY and buy a few $ worth of parts -- a three-prong AC mains cord, a suitable coaxial DC plug, and a length of 2-conductor cable (ordinary 18 AWG "zipcord" will do) to carry the DC to the amp -- in order to get it connected up, but IMO it's much more than worth that modest cost and effort.

HJS-480-0-48 SMPS

Looks nice. Can't find it at $25 but I'll keep an eye.
I have the A04 model with the 32V 5A Aiyima is selling on their site, which appears to be the same one Amir used in his review.

 

[Bruce Morgen]

Google is your friend.
https://www.ebay.com/itm/Douk-Audio...Supply-Adapter-US-EU-UK-AU-Plug-/254568008802

@Bruce Morgen
Yes the TI specs says 48v is optimal (with reference board) but there has been chatter in the community that these amp are not built to handle 48v.
I not an expert in this. Maybe you comment further on that ?

Aiyima explicitly states otherwise -- and, although they may be playing a litle fast and loose with audio specs, it would be unwise for them to specify a DC supply voltage likely to cause failures and thus cost them warranty replacement (+ shipping!) money. In my system, the SMPS output is set to 48.9 VDC unloaded, which drops to 47.5 VDC when the A07 is turned on and to a low of "47-point-whatever" VDC when the music is turned up as loud as l can endure. So far, not even a hint of audible distortion or even enough SMPS heat-up to turn on its cooling fan, let alone any indication of an impending failure. I think Amir's tear-down will reveal that the internal filter cap rating is 50 VDC, which is probably the practical limit for powering the A07. Of course, I've only been using the thing for months and not years, so take my testimony with a grain of salt in regard to long-term reliability at the voltages I mentioned.

 

[Bruce Morgen]

Based on many complaints on short life time of the amp, I guess there are thermal issues if 48V PSU is used and low impedance load. Local overheating and death of the chip.

Well, I could understand that if "low impedance load" means less than the 4 ohm lower limit for BTL mode noted in the TI data sheet -- or if the failures occurred when feeding the amp a steady test tone rather than actual music. So far in my experience, playing it loud AF with 4 ohm loads doesn't even heat up the top of the amp enough to make it hand-unfriendly. I might try to devise a method for thermally coupling the heat sink to the case top for additional cooling, which shouldn't be all that difficult given a little ingenuity.

 

[Bruce Morgen]

Looks nice. Can't find it at $25 but I'll keep an eye.
I have the A04 model with the 32V 5A Aiyima is selling on their site, which appears to be the same one Amir used in his review.

I can't find it that cheap nowadays either -- I guess I just lucked out on eBay last year!

 

[amirm]

Teardown just posted: https://www.audiosciencereview.com/forum/index.php?threads/aiyima-a07-tpa3255-tear-down.19020/

 

[daftcombo]

I just ordered one.

Thinking about this power supply to power it.

 

[Bruce Morgen]

I just ordered one.

Thinking about this power supply to power it.

Think again IMO -- it offers insufficient current sourcing to take advantage of what the TPA3255 can do and has the wrong connector for this particular amp.

 

[Zek]

Thinking about this power supply to power it.

It's only 3,34A - that's not enough for driving power amp.

 

[daftcombo]

It's only 3,34A - that's not enough for driving power amp.

It is not a lot, but Amir tested it with 48 volt/3 amp. See introduction of the review.

More amperes is a lot pricier.

 

[daftcombo]

Think again IMO -- it offers insufficient current sourcing to take advantage of what the TPA3255 can do and has the wrong connector for this particular amp.

If you can link me to something with the good connector and all the safety certificates, I'd gladly buy something lese.

 

[Bruce Morgen]

If you can link me to something with the good connector and all the safety certificates, I'd gladly buy something lese.

To get the most out of this sort of amp, you have to do some DIY and take responsibility for the safety issues rather than relying on formal certifications. Since I've gone that route exclusively, I haven't looked for a ready-to-go, no-DIY solution -- sorry I can't help. Back when I used a TPA3116 chip, I was able to find a 24VDC 10A power brick -- but I don't know if anyone offers a 48VDC 10A equivalent.

 

[Ariamella]

If you can link me to something with the good connector and all the safety certificates, I'd gladly buy something lese.

https://www.aliexpress.com/i/4000970577819.html here you go

 

[Eetu]

Nice review (+ teardown)!

This is the same chip as in the MiniDSP SHD Power?

If using a 32V 5A or other lower-than-recommended-power PSU it's better to get a TPA3251 based amp such as the A04, should be slightly cleaner and have less noise. I have the A04 on it's way, can't wait to compare it to my NAD power amp.

 

[daftcombo]

https://www.aliexpress.com/i/4000970577819.html here you go

I asked for a power supply.

 

[TheWalkman]

Think again IMO -- it offers insufficient current sourcing to take advantage of what the TPA3255 can do and has the wrong connector for this particular amp.

Any comments on this PS to power it? I’m gathering that Mean Well makes quality product and assuming this addresses Amirm’s safety concerns.

https://www.jameco.com/z/GST220A48-...-Power-Supply-DIN4-Plug-Level-VI_2226513.html

It appears plug adaptors are cheap. (I believe this is the correct barrel plug): https://www.jameco.com/shop/ProductDisplay?catalogId=10001&langId=-1&storeId=10001&productId=2309151

Of course the power supply costs more than the amp, but who ever followed logic when searching for the holy grail of Class D amps.....

 

[Ariamella]

I asked for a power supply.

The unit includes a PSU so you don't even need to worry about it

 

[Willem]

I don't know about US prices, but here in the Netherlands a 2x100 watt Yamaha AS210 is only 189 euros including value added tax. For that you get multiple inputs including MM, balance, loudness and tone control, and reliable quality.

 

[DuncanTodd]

I don't know about US prices, but here in the Netherlands a 2x100 watt Yamaha AS210 is only 189 euros including value added tax. For that you get multiple inputs including MM, balance, loudness and tone control, and reliable quality.

Part of the fun here is finding dark horses.

 

[sejarzo]

Can these be modified to run bridged mono?

Perhaps you don't need to modify anything and just buy a couple of these:

https://www.amazon.com/Subwoofer-Amplifier-Full-Frequency-Switchable-TPA3255D2/dp/B07VD46PY9

 

[Bruce Morgen]

It is not a lot, but Amir tested it with 48 volt/3 amp. See introduction of the review.

More amperes is a lot pricier.

Not if you're willing to do some DIY -- it's the ready-to-go power brick solutions that get pricey when you need more volts and amps, whereas suitable industrial SMPSs are pretty reasonably priced.

Any comments on this PS to power it? I’m gathering that Mean Well makes quality product and assuming this addresses Amirm’s safety concerns.

https://www.jameco.com/z/GST220A48-...-Power-Supply-DIN4-Plug-Level-VI_2226513.html

It appears plug adaptors are cheap. (I believe this is the correct barrel plug): https://www.jameco.com/shop/ProductDisplay?catalogId=10001&langId=-1&storeId=10001&productId=2309151

Of course the power supply costs more than the amp, but who ever followed logic when searching for the holy grail of Class D amps.....

A good SMPS is actually more complex and has a higher parts count than this amp, in which all the complexity is packed into the output chip.