Will any of the D-amps run on 500ma?

[m0b1liz3]

I have a guitar pedal board power supply that has a 12v and 18v at 500ma. I was thinking I could put a low power Class D amp into a pedal if I could get it to run at 500mA instead of 2-5A.

 

[easp]

Maybe try a PAM8610, or a PAM8404/6 with a buck-converter? Boards are cheap on ebay, $1US, or less.

 

[m0b1liz3]

Never used a buck converter but like the idea. Question is if I can fit both into a pedal enclosure.

 

[m0b1liz3]

Is there a simple equation to figure out the voltage at 2A if I am using a buck converter with 18v 500mA input?

Also, are there other low power amp boards less prone to noise? I read a few threads about noise with PAM versions.

 

[DownSouth]

P = I X E
Power = current times voltage.

So 18v @ 500 ma = 9 watts.
so 9 = 2 times ? drum roll please 4.5 V Close to USB spec.

Buck converters are ~ 85% efficient so use 9 X.85 for watts out. 7.7 watts.

A class D audio amp is 80-90% efficient so you can get 5 watts of audio out which should be enough.

 

[theAnonymous1]

Just get any board that can take 18V like TPA3116/8 and limit the gain. You should be able to get around 2W (1W per channel) with 8ohm speakers. That's enough for casual listening if the speakers have decent efficiency.

EDIT: It might be difficult to fit one of those boards in a pedal. Maybe this combo instead...

https://www.aliexpress.com/item/HT6...-Audio-Power-Amplifier-Board/32572143474.html
https://www.aliexpress.com/item/DC-...7V-28V-to-5V-3A-Fixed-Output/32636482278.html

 

[lutkeveld]

Just get any board that can take 18V like TPA3116/8 and limit the gain

Or just use the Plimit function

 

[Pafi]

500 mA of average current is enough for a very high volume with audio signal and a real speaker, if you somehow provide also the high peak currents. How? With a big capacitor, and maybe with a current limiter between PSU and cap if the PSU cannot handle overload properly. No need to limit voltage this way.