AIYIMA A07 TPA3255 amplifier with MW RS-100-24 SMPS power supply (measurements)

[pma]

I often play that system seriously loud, and have NEVER had the amp get "switched off," even after several hours at that volume.

Sorry, I am interested in exact data only when testing the amplifier. You "often" (means what?) play music - translated as undefined time, undefined average power value with undefined signal. As I explained, I want the amp to meet the defined specs, not individual undefined conditions based on subjective opinion, not YOUR conditions but repeatable reliably defined test conditions.
TPA3255 may have sophisticated protection circuitry, but the undersized heatsink in a closed too small unvented box is definitely not sophisticated. It is what it is, a cute toy that can bring a lot of fun, but definitely not a serious amplifiers that meets standard specs. Not mentioning the ridiculous 2 x 300W they declare. Not a second it would give that power.

 

[Bruce Morgen]

Sorry, I am interested in exact data only when testing the amplifier. You "often" (means what?) play music - translated as undefined time, undefined average power value with undefined signal. As I explained, I want the amp to meet the defined specs, not individual undefined conditions based on subjective opinion, not YOUR conditions but repeatable reliably defined test conditions.
TPA3255 may have sophisticated protection circuitry, but the undersized heatsink in a closed too small unvented box is definitely not sophisticated. It is what it is, a cute toy that can bring a lot of fun, but definitely not a serious amplifiers that meets standard specs. Not mentioning the ridiculous 2 x 300W they declare. Not a second it would give that power.

I am in no way believing -- let alone defending -- the exaggerated specs that are typical of sub-$100USD amps. There are no "standard specs" when it comes to this category of products, but based on 5+ decades of experience this thing can put out well into three digits of power into four ohm loads with both channels driven given enough volts and amps. I'm aware that the heat sink and enclosure are far from optimal with regard to the chip's potential, which is well documented in the TI data sheet that neither of us are in a position to dispute -- I'm just testifying that those shortcomings have zero impact on how it performs here. I don't use it with test equipment and a vastly underspeced power source, I use it as part of a music system with a suitable SMPS and AFAICT it plays its assigned role flawlessly -- at least as well and in some respects better than the "audiophile" power amps I owned and loved back in the day -- for a price so low it beggars the imagination. Enough said.

 

[pma]

OK, so this is how I built the Mean Well SMPS into the aluminium case.

 

[Bruce Morgen]

The power supply used in this new test thread is switched mode power supply Mean Well RS-100-24, rated at 24V/4.5A (108W).

You do know that you can buy a 24VDC 10A "power brick" for about $50USD -- I got one of those via Amazon for use with a TPA3116-based "2.1" amp for TV sound -- and thus avoid all that DIY effort, right? The only thing you'd lose is the ability to tweak the voltage up a few volts but, with more than double the current available, my educated guess is that you'd actually get better performance.

 

[ironhorse128]

OK, so this is how I built the Mean Well SMPS into the aluminium case.

View attachment 112093

View attachment 112094

Can you run the meanwell PS inside such a small enclosed box without ventilation holes powering a tpa3255 board? Would be interesting to know. I assumed I would need ventilation holes.

 

[pma]

Can you run the meanwell PS inside such a small enclosed box without ventilation holes powering a tpa3255 board? Would be interesting to know. I assumed I would need ventilation holes.

It seems that yes. The box is not very small, dimensions are 170 x 270 x 70 mm and the PSU dimensions are 100 x 155 x 40 mm. So the box for the PSU is much bigger than that of AIYIMA A07, and it is a 108VA power supply. However, I will see after longer operation and I will measure inside temperature.
Would you think that much smaller plastic boxes of the power supplies recommended by the manufacturer and used by Amir in his test would have better heat transfer into the ambient air?

 

[pma]

Can you run the meanwell PS inside such a small enclosed box without ventilation holes powering a tpa3255 board?

Temperature test results

I have made a temperature test at 1 x 50W/4ohm/1kHz continuous sine power, duration 45 minutes. The temperature has settled after 30 minutes after start, then keeping same values.

Results after 45 minutes
Temperature ambient inside the box with MW SMPS : 39°C
Temperature at the top surface of the AIYIMA A07 metal case : 41°C
Temperature at the surface of two 200W load power resistors mounted on heatsink : 75°C

Factory specs allow for 70°C working temperature for the MW SMPS

Factory temperature rise test is made at 50°C ambient temperature for 12 hours

So I am sure that we are at the safe side.

To me, AIYIMA A07 + MW RS-100-24 SMPS in the Al box make a nice combo rated at 2 x 50W/4ohm. Together with Magnat Monitor Supreme 102 speakers they make a nice workbench desktop system to me.

 

[ironhorse128]

Temperature test results

I have made a temperature test at 1 x 50W/4ohm/1kHz continuous sine power, duration 45 minutes. The temperature has settled after 30 minutes after start, then keeping same values.

Results after 45 minutes
Temperature ambient inside the box with MW SMPS : 39°C
Temperature at the top surface of the AIYIMA A07 metal case : 41°C
Temperature at the surface of two 200W load power resistors mounted on heatsink : 75°C

Factory specs allow for 70°C working temperature for the MW SMPS
View attachment 112233

Factory temperature rise test is made at 50°C ambient temperature for 12 hours
View attachment 112234

So I am sure that we are at the safe side.

To me, AIYIMA A07 + MW RS-100-24 SMPS in the Al box make a nice combo rated at 2 x 50W/4ohm. Together with Magnat Monitor Supreme 102 speakers they make a nice workbench desktop system to me.

Awesome. Thanks for testing. This is definitely a good combination. The meanwell PS is is a great and safe option for the a07.

 

[pma]

Isn't it crazy? The proper SMPS power supply placed in the proper box is considerably bigger than the amplifier. Because the output speaker binding posts of the AIYIMA A07 are so tiny with too small spacing, I need to use a DIY built adapter if I want to connect this amp to my regular speakers with regular cables and latching banana plugs . So the "tiny" design has gone. However, it sounds good .

 

[Anthony Rehm]

You do know that you can buy a 24VDC 10A "power brick" for about $50USD -- I got one of those via Amazon for use with a TPA3116-based "2.1" amp for TV sound -- and thus avoid all that DIY effort, right? The only thing you'd lose is the ability to tweak the voltage up a few volts but, with more than double the current available, my educated guess is that you'd actually get better performance.

Fair enough.

Isn't it crazy? The proper SMPS power supply placed in the proper box is considerably bigger than the amplifier. Because the output speaker binding posts of the AIYIMA A07 are so tiny with too small spacing, I need to use a DIY built adapter if I want to connect this amp to my regular speakers with regular cables and latching banana plugs . So the "tiny" design has gone. However, it sounds good .

Another solution to keep the cords at bay is to grab from Ali a metal cover for Creality3D Ender-3S power supply. It should suit Mean Well LRS-350-48.

https://aliexpress.ru/item/32971586...earchweb0_0,searchweb201602_,searchweb201603_

https://aliexpress.ru/item/33062727...earchweb0_0,searchweb201602_,searchweb201603_

 

[SAC_2]

Can you recommend a PSU upgrade for this that is plug and play and safe? I plan to have this plugged in 24/7.

 

[Zoomer]

Another solution to keep the cords at bay is to grab from Ali a metal cover for Creality3D Ender-3S power supply. It should suit Mean Well LRS-350-48.

https://aliexpress.ru/item/32971586...earchweb0_0,searchweb201602_,searchweb201603_

https://aliexpress.ru/item/33062727...earchweb0_0,searchweb201602_,searchweb201603_

Neat! I need one though with a height of 50mm instead of 30mm
On STLfinder there are plans to download, but obviously not assembled like the one on aliexpress...

 

[Angeldust77]

Temperature test results

I have made a temperature test at 1 x 50W/4ohm/1kHz continuous sine power, duration 45 minutes. The temperature has settled after 30 minutes after start, then keeping same values.

Results after 45 minutes
Temperature ambient inside the box with MW SMPS : 39°C
Temperature at the top surface of the AIYIMA A07 metal case : 41°C
Temperature at the surface of two 200W load power resistors mounted on heatsink : 75°C

Factory specs allow for 70°C working temperature for the MW SMPS
View attachment 112233

Factory temperature rise test is made at 50°C ambient temperature for 12 hours
View attachment 112234

So I am sure that we are at the safe side.

To me, AIYIMA A07 + MW RS-100-24 SMPS in the Al box make a nice combo rated at 2 x 50W/4ohm. Together with Magnat Monitor Supreme 102 speakers they make a nice workbench desktop system to me.

Hi.
I used MW LRS-150-24 with old HDD 3.5 case with ventilation holes. Easy and efficient. Thanks for your idea and work.

 

[hoverdonkey]

Isn't it crazy? The proper SMPS power supply placed in the proper box is considerably bigger than the amplifier. Because the output speaker binding posts of the AIYIMA A07 are so tiny with too small spacing, I need to use a DIY built adapter if I want to connect this amp to my regular speakers with regular cables and latching banana plugs . So the "tiny" design has gone. However, it sounds good .

Thanks for all your info on power supplies for the A07, @pma , you have been an excellent guide.

 

[hoverdonkey]

Hi.
I used MW LRS-150-24 with old HDD 3.5 case with ventilation holes. Easy and efficient. Thanks for your idea and work.

Great idea, thankyou, I was just starting to think about a cheapskate way to box-up my just-ordered LRS-100-24. I have an old external drive gathering dust up in the loft. Somewhere...

 

[hoverdonkey]

I connected 47nF/1000V capacitor to reduce output HF noise a bit

Hi


I would be grateful to know to how you chose this value & type capacitor:

Value - Is 47nF optimal or would bigger be any better?

Type - Is the Tesla TC209 polyester film type? Does the type matter in this application?


Thanks

 

[Deleted member 9685]

As a comparison, many preamps or dacs connected to the power amplifier with 27dB gain produce more hiss in my tweeter.

What is the gain of AIYIMA A07?

 

[friarminor]

Isn't it crazy? The proper SMPS power supply placed in the proper box is considerably bigger than the amplifier. Because the output speaker binding posts of the AIYIMA A07 are so tiny with too small spacing, I need to use a DIY built adapter if I want to connect this amp to my regular speakers with regular cables and latching banana plugs . So the "tiny" design has gone. However, it sounds good .

View attachment 112884

Same thought and situation. Not in photo - E30 DAC, old Project Dock Box for Spotify, Rega Fono for RP1 Turntable. These small gadgets are all I can fit (and usually stow away in their boxes when I want to clear my mind and sight.

 

[pma]

What is the gain of AIYIMA A07?

I measured 32.35 dB at full volume.

 

[Scrufboy]

No arguing from my side, I show these results because I think they are interesting. I like to go in deep and to find consequences. As the ASR declares itself as a forum with scientific approach, I hope it is fine to try to show something more than a cook-book .

Why do we have zero to few, if any sources for enclosures for these open cage units?