Volume Pedal

[soggybag]

I have an old Ernie ball volume pedal and I'm trying to get it working again. Can anyone point me to a schematic?
I thought I had it wired up as the original but it doesn't seem to be working.
Of course I am a total amatuer.

[bwanasonic]

Make sure your problem is electrical, not mechanical. I have had the problem of the pedal not rotating the pot. A continuity tester or DMM should go a long way towards figuring out where the problem is.

Kerry M

[toneless]

Hi soggybag.
Make a search at the forum with your "subject" and you will find more than you want!!!

Don't worry. It's a simple design.

[Paul Marossy]

That's so simple a schematic isn't really necessary. It's basically a volume control - signal goes in one outside lug, the other outside lug goes to ground. The wiper is the signal out. I believe that all of the passive Ernie Ball volume pedals use a 1Meg audio pot.

If it doesn't work, it's one of a few things:

1. The pot is broken (not likely, but not impossible)

2. The allen screw on the brass spindle part that attaches to the pot has come loose and it longer turns the shaft of the pot.

3. The pot is somehow frozen and the string is just slipping on the spindle. Not likely because it would definitely bind up on you.

4. One or more of the quick connect terminals on the pot have come loose and is not making an electrical contact anymore.

5. The second string inside is broken - you should have two seperate strings inside the pedal with a spring connecting both of them. (If this is not the case, then if you have to take the thing apart, you may find it useful to get a hanger wire and fashion a tool out of it so you can pull the spring that joins both strings to disconnect them. It's kind of a PITN working on one, but I made one of these tools and it was a lifesaver the few times I have had to take my Ernie Ball volume pedal apart!)  

[bwanasonic]

There may also be a small PCB with a resistor and a switch for two different pot tapers ( that's how the 6166 I have is). Something like a faulty jack could be a problem as well.

Kerry M

[Paul Marossy]

Ah, yes, I forgot about a faulty jack...

[Hal]

make sure both cables are good.

[bwanasonic]

And beware the classic pitfall! Make sure your guitar has strings on it!

sorry, that was just silly


Kerry M

[Paul Marossy]

And beware the classic pitfall! Make sure your guitar has strings on it!

:lol:

[soggybag]

The pedal has two pots that are both 250K. There is also a small cap about .22pf (I think) wired between the input and output jack, between the two tips. The pots seem to be wired in such way that the signal goes through both. The smaller pot on the side seemed to be bad. It had spots where it showed higher resistance than it should show and other spots where it showed a resistance that looked correct. When I measure the resistance between the input and the output I get something from 0 to 130K.

I thought this would be any easy fix too, but it's stumping me. This is why I wish I could see the schematic to check and make sure the parts are all correct.

[Paul Marossy]

Ah, I was under the impression that we were talking about a standard mono volume pedal. It sounds like you have the panning stereo version?

[soggybag]

The pedal has two pots one connected to the pedal the other has a little knob on the side. The signal comes into the one lug and the wiper of the small pot and the side lug of the pedal pot. The wiper of the pedal pot and the open lug of the side pot go to the output.

Code Select Expand


------------------------
|            |         |
\ 250k       v 250k    |
/<--------/\/\/\-------|
\     |                |
|     |                |
|     |-----||---------|
|     |                |
GND   |                in
    out

[Paul Marossy]

Oh sorry about that, I forgot that they also had a version with a secondary volume knob to set the min/max volume.  :oops:

I honestly don't know how those are wired. Anyone else have some insight?