Pedal Power Question

kinski · Post by **kinski** » 15 Jan 2013, 19:53

So, I'd like to build the GGG Center Stage Reverb, that uses an actual spring reverb pan.

I'd love to be able to install it into the back of an amp and forget about it. However, it seems the unit would need 18v (or 9v with a charge pump).

My question is this...would it be at all possible to power the reverb using the amp's power somehow? It would be much preferred to running a separate power supply to the reverb in the back of the amp.

Ice-9 · Post by **Ice-9** » 15 Jan 2013, 22:04

Yes indeed, it would not be much of a problem to power it from the amp, but it would help if we knew what amp you wanted to use so a schematic can be used to tell you where it might be possible to get the supply from.

kinski · Post by **kinski** » 15 Jan 2013, 22:50

Fantastic! Thanks for the help!

Here is the reverb layout I'd like to use:

The amp is a reissue Gibson GA-5 Les Paul Jr Goldtone (5 watts).

I can't seem to find a schematic for this amps. It has 1 12ax7 and 1 EL84.

Here are some pics of the guts. In the meantime, I'll keep looking for a schematic! There are pics I found online. Let me know if there is anything specific you need to see and I can open mine up and take some pics.

Ice-9 · Post by **Ice-9** » 17 Jan 2013, 15:56

Having a quick look at your pictures it looks like there will be about 350 volts at the rectifier stage and the only low voltage power will come from the transformer windings that supply the valve heaters. If I am correct and this is a high voltage valve amp, if you are unsure about what you are doing then it can be very dangerous to mess about with it. So I am assuming the fact that you are having to ask this question in the first place means you have very little expierence with power supply and high voltage so it might be better to look at ather solutions, possibily you could use a 9v wall wart wired internall to the amp to supply your low voltage to the reverb.

If possible post the correct schematic for your amp and maybe there is an easier way to look at this.

kinski · Post by **kinski** » 17 Jan 2013, 16:08

Thanks for your response. You are correct, very little experience working with tube amp power. I've been looking for a schematic everywhere but can't seem to find one. I'll keep looking.

deltafred · Post by **deltafred** » 18 Jan 2013, 10:11

kinski wrote: I can't seem to find a schematic for this amps. It has 1 12ax7 and 1 EL84.

Try http://www.gibson.com/service/tech/schematics/

(That schematic shows a tube rectifier where yours has solid state.)

It is possible to use the heater supply to derive power for the Rangemaster but you might be better off fitting a separate (small) power supply for it fed from the mains after the on/off switch.

I will echo the advice to be extremely careful if/when you mess with it. Tube amps can be dangerous in the wrong hands.