Adding 9v out to amp


Well-known member
I'm adding a 9v out to the back of my amp to power my always-on reverb pedal that will live inside it. I never adjust it, so it's taking up space on my board, why not free that up and give myself another project? The amp is my SLO-30 Clone I built last year.

Here's the schematic I've come up with, tapping off the 36v bias supply of the amp. Honestly I have no idea if this will work or fuck up the bias of my amp, but I think it's worth a try. All the threads in other "stodgier" places of the internet all said "why?" and "Just buy a wall-wart, noob" and the like, so I thumb my nose at them and drew this up today. The first LM317 drops the 36v to 9-ish to feed into a trace of one of the taps on @Robert's 4-tap converter/isolator. I think I could do without the rectifier circuit, but nervous about adjusting any of that circuit as I'm not intimately familiar with the IEB isolator and L7805.

If anyone has suggestions on how to lower part count, eliminate excessive capacitors, I'd be grateful. I chose the 317's resistors based on values I have a lot of, so I'd rather not adjust those unless there's a good reason.

Thanks all!


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I assume your 36V supply is already rectified DC voltage?

If so, you don't need the additional bridge rectifier.

If not, you need to move the rectifier between the 36V supply and the LM317.