Beavis Audio Devolt questions

[nieh]

Okay, so I ordered all of the parts to build one and I did. When I'm using it when I turn the knob to limit the volts turning in completely the other way only makes a slight change in the sound of the pedal, and the led just dims a bit. I used the exact parts and wiring diagram. Whats going on?

[nbabmf]

Did you run the remaining leg of the pot to ground as a voltage divider or leave it configured as a variable resistor?

[nieh]

Did you run the remaining leg of the pot to ground as a voltage divider or leave it configured as a variable resistor?

The third lug isn't wired to anything.

[nieh]

It's wired like this,

[nbabmf]

Try using a jumper to ground that last lug. You might end up with way too low a voltage even when maxed, but it's worth a shot.

What kind of pedal are you using it to (de)power? Some don't really do anything.

[nieh]

What should I ground it to?

And I've tried it on a crush fuzz a big muff a phaser a CC/DC and a few overdrives and distortion pedals.

[nbabmf]

Ground is the black wire.

[devnulljp]

Try it on an old Dyna Comp or a nice Ge Fuzz Face

[smallsnd/bigsnd]

don't ground the third lug.
what happens when you turn it all the way down? you short power to ground... not good. the pot will probably catch on fire.

IF you want to do something similar to that, add a limiting resistor between the third lug and ground - i'm not sure what would be best, but i'd just go with a 1k or so to start.

[nbabmf]

Oops, left that part out. I often take these things for granted when posting.

[ashdown]

Oops, left that part out. I often take these things for granted when posting.

did you figure out what was wrong? i was planning on building one of these in the really near future

[multi_s]

don't ground the third lug.
what happens when you turn it all the way down? you short power to ground... not good. the pot will probably catch on fire.

IF you want to do something similar to that, add a limiting resistor between the third lug and ground - i'm not sure what would be best, but i'd just go with a 1k or so to start.

There will be no short. Imagine we do put pin 3 to ground...

With the wiper all the way to lug 3... So the resistance in between 1 and 2 is 10k. The resistance between 2 and 3 is 0 ohms. Since The input power is on pin 1 that puts 10k between the input power and ground. Far from a short.

Imagine a voltage divider.
edit

not to say you should have to ground lug 3 do this to get it to work, just that you shouldn't worry about anything exploding. starving circuits has unpredictable (and sometimes negligible) effects.

[smallsnd/bigsnd]

ah yes! whoops. early on in my pedal building i wired a pot from 9v to the MIDDLE lug of a pot, one side to ground, the other to the circuit 9v and there was some smoke... not the good kind.

[MEC]

Double check that you are not plugging your power supply into the "out" side of the starver and then going from the "in" side to your pedal. Also, how are you connecting the starver to you pedal to be starved? If you are using a one spot type daisy chain you will have to power your starver separately then run the daisy chain starting from the starver "out". If you have a multimeter you can measure the voltage change as you turn the pot to see exactly how much the voltage drops. By doing this you can determine if the starver is doing it's job and it's just the pedal not reacting much to the voltage drop.

Hope this helps

[Jack Deville]

The suggestion/circuit suggested above creates an adjustable resistance in series with the power source.
This series resistance will limit available current as well as potentially create a voltage drop.
Potential voltage drop will not be consistent circuit to circuit as the voltage drop is dependent on the Thévenin resistance of the circuit drawing current from the resistance/current-source.

Consider using an adjustable voltage regulator circuit for this application.

I hope this information is found useful and relevant.