Building a Volume Pedal

crimson_basser · August 20, 2009, 03:09:15 PM

Im new to the forum so if there is a thread covering this already, please feel free to link me.

I want to build a volume expression pedal. Im just not entirely sure what parts I will need.
Im planning on buying an expression pedal kit to start with.

I know Ill need two 1/4 inch jacks, but as far as inductors, pots etc, im not entirely sure how to go about it.
Any advice, links etc are more than welcome

Thanks in advance.

Auke Haarsma · August 20, 2009, 03:17:07 PM

have a look at the tonepad.com volume pedal retrofit. You may like it!

http://tonepad.com/project.asp?id=12

crimson_basser · August 20, 2009, 04:00:35 PM

Note: this isnt a volume boost pedal, im talking about an expression/swell pedal.

So is all that circuitry required? Cause in my head (and i may be totally wrong) you would only need a volume pot
(similar to a wah pot ) that attaches to the foot pedal...

Rescue me please!

Hahaha

tiges_ tendres · August 20, 2009, 05:16:53 PM

Do you want a volume pedal or an expression pedal? Those are two different things.

If you just want a volume pedal then yes, you would just need a volume pot in a wah shell. The extra circuitry in the link kindly provided is supposed to be an improvement over standard designs. I'm not sure what it does. Is it buffered perhaps?

Ripthorn · August 20, 2009, 05:19:11 PM

Yeah that is a buffered in/out pedal linked to. If you don't want buffered, you don't need it.

crimson_basser · August 20, 2009, 07:38:01 PM

I want an expression pedal that controls the volume of my instrument.

Sorry for the confusion, I wasnt sure what the correct term was,
Ive seen them called several things.

Paul Marossy · August 20, 2009, 10:08:13 PM

Quote from: crimson_basser on August 20, 2009, 07:38:01 PM
I want an expression pedal that controls the volume of my instrument.

Sorry for the confusion, I wasnt sure what the correct term was,
Ive seen them called several things.

That's traditionally called a volume pedal.

sean k · August 21, 2009, 01:07:57 AM

Indeed, all you need is the pot but the problem there, and you may decide to live with it, is that the extra volume pot ends up arallel with the one on the guitar and this loads the signal slightly and will result in a little loss of highs. You could add a switch to the guitar to bypass your volume so when you use the volume pedal you basically still have the same value pot as the guitar has. The problem with that kind of setup is that you may not neccessarily have the volume pot direct off the guitar and may put it after effects to ground the whole chain. In that case the 250k or 500k pot may not be quite right agin as the outputs from fx are usually 100k so they can feed the 1M input thats coming up so a 100k then a 250k will be in parallel and, well it just gets confusing having the exact right pot for the exact right placement whereas the circuit that is in the link solves several problems.

Number one it eliminates scratchy pots as its just used to divide a voltage to control a VCA . Theres no signal on it. And it attends to the impedance problem by having the output sit at 100k. CA3080's are supposedly a little hard to find these days but its not a tricky ircuit and the man is offering a PCB to build it on so it's not really any more difficult than what you are ontemplating anyways, except buying more parts and soldering them up. But if you're still intent on having a pot alone then let us know what the guitar volume pot resistance is, if you want to use it straight off the guitar, or what the output pot or resistor is on the fx you want to use after... and what will usually come after it.

crimson_basser · August 21, 2009, 03:54:51 PM

Well, my only intention is to use it as a swell effect.

It will only be on in certain parts of songs to swell the guitar in and out, it wont be used for
anything other than that. So even if there is a slight loss of highs or any degradation of sound
(as long as its not ridiculous) it's fine by me.

Basically, it will be placed first in the signal chain, and it will have a bypass switch
either built into it or attached to it. After the volume pedal will be my 2 channel effects loop
with a range of effects in each loop including delay, reverb, chorus and tremolo in one
and several distortions/fuzzes in the other.

I bought an expression pedal kit and several components from Small Bear, so when everything
arrives ill put it together and see what happens. I have no problem experimenting a bit

That is after all, the fun of DIY pedal making is it not?

News:

Building a Volume Pedal