Simulate a dying battery mod

[jfrey]

Well, say I wanted to build it into a pedal. With a 10k pot there isn't a noticeable effect. Would increasing the pot value fix this? Or do I need to do something else?

[MEC]

If every thing is wired right you should notice some difference with a 10k pot. Do you have a Multimeter? If so set the meter to measure voltage on the nearest setting above 9v (probably 20v), ground your - (black) lead to the ground lug on the back of the 9v tap then put the + (red) lead on the DC+ pad on the board where you have connected your wire from the pot. Plug in the adapter and turn the pot all the way clockwise you should have a reading at 9.6 or below. Slowly rotate the pot and watch to see if the voltage changes if it goes below 8v, and it should, you should notice a difference for sure. If it doesn't change at all you probably have a bad pot. You can check it with your meter http://www.youtube.com/watch?v=o4jtJUedlHg&feature=related

If none of this helps post some pics and maybe someone can spot the problem.

[McSpunckle]

He's right in that if you're not hearing anything with the 10K pot something's wrong, or the pedal you're using is regulated to a low-ish voltage or has some other weirdness going on.

Though, I've never used the voltage divider method and thought it worked better than the series resistance method. The pedals always seem to gate off to nothing way too fast. Raising the pot value just makes that worse. Usually, with just a 10K pot in series, you can get the pedal down to where it's barely operating. At least with fuzz pedals.

[jfrey]

The pot was broken. Replaced it with a new one. Doesn't make a huge change in the sound but there is some. I set up the enclosure for testing though so that's fine. Nothing that is part of or attached to the enclosure is actually soldered to the board. Everything is socketed so I can swap out boards whenever I come up with something new. The test enclosure is set up with volume, gain, and starve pots, transistor swapping switch, and a center off toggle with two diode clipping options.

[MEC]

He's right in that if you're not hearing anything with the 10K pot something's wrong, or the pedal you're using is regulated to a low-ish voltage or has some other weirdness going on.

Though, I've never used the voltage divider method and thought it worked better than the series resistance method. The pedals always seem to gate off to nothing way too fast. Raising the pot value just makes that worse. Usually, with just a 10K pot in series, you can get the pedal down to where it's barely operating. At least with fuzz pedals.

I like the voltage divider because once you find the cut off/gate off point, say 6v, you can adjust your fixed resistor so that 6v becomes the bottom end of the pots range and the adapters output, say 9v, will be the top end. The whole sweep of the pot would be from 6v to 9v making the tuning finer than if the sweep was 0v to 9v and you never actually hit the cut off point.

The pot was broken. Replaced it with a new one. Doesn't make a huge change in the sound but there is some. I set up the enclosure for testing though so that's fine. Nothing that is part of or attached to the enclosure is actually soldered to the board. Everything is socketed so I can swap out boards whenever I come up with something new. The test enclosure is set up with volume, gain, and starve pots, transistor swapping switch, and a center off toggle with two diode clipping options.

Now you have to post pics!

[jfrey]

I set up the additional knob and switches on the outside - superglued onto electrical tape. I want to remake this test enclosure in a larger pedal with more options so I didn't want to do any drilling or anything and potentially waste this enclosure.

The current pedal consists of 3 pots, 2 toggles (1 of which is center off), a footswitch, led, 6 resistors, 2 caps, 2 transistors, 4 diodes, jacks, etc. It's my prototype overdrive/fuzz (depending on how you toggle the effect). My first original design.

[MEC]

Awesome! I've planned to do something like this but never gotten around to it.