Looking into Power Amp Build based on TPA3118

[80k]

I've been getting into the world of amplifiers in pedal form factor, and am interested in building a power amp based on the TPA3118 chip (2x30W or 60W bridged). I have a few boards coming from Aliexpress so it will be some time before I get my hands on them.

My primary goal is to build a single power amp into a 1590B Hammond box with a single volume knob. The input signal will already be the wet signal of my stereo delay pedal that has already gone through the preamp of my Quilter Interblock and sent through the effects loop. The dry signal from the delay will go back into the return of the Quilter, and the wet signal will go into this power amp and into another cabinet.

I am planning to use this image, which I found on The Gear Page forum: https://image.ibb.co/mHct29/30-W-TPA3118-Power-Amplifier-1.jpg

I have never built anything other than pedals running off 9V power sources, so wanted to ask a few questions pertaining to projects like this. So far this is my understanding:

• I'll want a diode that can handle 3A. One recommendation was the 1N5408.
• A laptop power supply supplying 19V is often used, from what I gathered.
• A need to make sure I use an isolated output jack as it should not share a ground with the rest of the circuit.
• Are the 22 gauge pre-bonded wires I get from Small Bear Electronics OK for this voltage?
• Are the small (16mm) alpha pots I usually use for pedals OK for this project?

I also had some questions on power supply:

• I have an HP laptop power supply that is 19.5V, 3.33A, and rated for 65W. Is this OK with a circuit that is 60W? Or do I need a beefier power supply?
• How do I determine the polarity and jack that can work with a laptop power supply? Any suggestions on supplier?

Any other advice would be appreciated. And curious if anyone else has built a power amp in a pedal form and any tips or ideas you might share.

Thanks!

[antonis]

I'd go for 5A diode (like BY500-50 or similar)..
22AWG is rated at 6.3 AMPERES (not volts) so you should be OK..
Jack's polarity is determined by multimeter..

Without additional information can say anything about pots or power supply adequacy..

[ElectricDruid]

What's happened to the negative power connection?!? I think like this, this amp might be a bit *quiet*.


Incidentally, the 16mm Alpha pot is ok for this job because it's only dealing with the input signal. The *output* signal would probably fry it.

[80k]

What's happened to the negative power connection?!? I think like this, this amp might be a bit *quiet*.


Incidentally, the 16mm Alpha pot is ok for this job because it's only dealing with the input signal. The *output* signal would probably fry it.

Oh good call, that must still go to the ground (probably to the tip of the input jack). I think that drawing must have a mistake. Thanks for catching that. 

[80k]

I'd go for 5A diode (like BY500-50 or similar)..
22AWG is rated at 6.3 AMPERES (not volts) so you should be OK..
Jack's polarity is determined by multimeter..

Without additional information can say anything about pots or power supply adequacy..

Thanks! I'll do a little bit more research, with regard to power requirements, etc.