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

[pma]

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

Because these units are primarily intended for industrial automation and IT technologies and are built in caseworks of the completed gear.

 

[howard416]

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...

An old micro PC case.

A cake pan. Punch out holes for ventilation.

A cookie tin. Punch out holes for ventilation. (Grounding may be tricky with the thin sheet material).

A cooking oil can. Punch out holes for ventilation. https://www.walmart.com/ip/Filippo-Berio-Extra-Virgin-Olive-Oil-101-4-Fl-Oz/10307311

A heavy-duty plastic box/tote. It used to be that plastic/fiberglass electrical enclosures were actually pretty cheap, but not anymore unfortunately.

 

[Joe Smith]

There'd be a market for these MeanWell supplies sold in nice cases, I think, like the one earlier in the thread. I did a lot of homebrew cigar box box builds when the 3116 amp boards first came out, but it got a bit wearying, and then I fried a NAD cd player chip when I had a static zap in winter to the metal volume knob of one of those amps.

 

[howard416]

There'd be a market for these MeanWell supplies sold in nice cases, I think, like the one earlier in the thread. I did a lot of homebrew cigar box box builds when the 3116 amp boards first came out, but it got a bit wearying, and then I fried a NAD cd player chip when I had a static zap in winter to the metal volume knob of one of those amps.

How would that be any different than in a beefier metal case though? You've got to ground them for safety, so...

 

[pma]

As this thread has been resurrected, please let me show THD vs. frequency plot of this amplifier measured at 43W/4ohm with 48kHz bandwidth. I thing it is interesting to show a comparison of the same kind of measurement made with Hypex NC252MP. No LC LPF measuring filter used.

 

[RDoc]

This is really excellent information. Thanks very much for doing all this!

 

[pma]

Some new measurements, with E1DA Cosmos ADC.

1kHz harmonic distortion is good, though with many high order harmonic products.
HF linearity (19+20kHz IMD) is poor, as with many other simple class D amplifiers.
Noise should be lower.
Absence of mains supply spuriae lines is worth mentioning, quite excellent result.

 

[Deleted member 58865]

Would a medical power supply improve SINAD or SNR?

 

[pma]

I am preparing to measure this little amplifier

WONDOM AA-AB31471 Class D Mono Amplifier Module TPA3110 30W 4 Ohm - Audiophonics

The Wondom AA-AB31471 is a small, simple and efficient Class D mono amplifier module. It includes a TPA3110 TI chip to enable it to provide a power of 30W for an efficiency of 90%, as well as a precise sound reproduction.

www.audiophonics.fr

so I was seeking for a SMPS power supply with 19Vdc voltage. I found one in my stock, which was originally a PSU for my very old notebook. The PSU looks like this

and seems to be the same unit that is recommended for the small Wondom amplifier

Power Adapter 100-240V AC to 19V 3.4A DC - Audiophonics

sector-adapter-supply-100-240V-to-19v-34a

www.audiophonics.fr

So I have decided to try this power supply with my AIYIMA A07 and I was very happily surprised with the result.

This is a spectrum of 1kHz/20W/4ohm

Quite low distortion and please note total absence of mains spuriae harmonics. Of course proper wiring of the measuring system is necessary to get it.


This is THD+N vs. output power

And this is THD+N vs. frequency at 20W/4ohm

With this power supply, we get clean 20W/4ohm and acceptable 30W/4ohm. The PSU construction is rugged, well built, and the unit I have has been in operation since 2010.