Wah clips badly.

[mcasey1]

Into a clean amp my wah is producing a bad clip at all heel positions when playing somewhat forcefully.  Transistor gains are nice and low.  It is a BYOC board with a Whipple inductor and an IC buffer.  Have no idea what is happening and it has been bothering me for a while.  Any suggestions on what to try?

Thanks,

Matt

[R.G.]

Debugging: What to do when it doesn't work.

[Paul Marossy]

It sounds like your circuit is distorting somewhere. Your transistors might be low gain types, but are you sure that you used the correct resistor values everywhere? You must have made a mistake somewhere.

An audio probe might be helpful in determining where it's happening.

[Joe Hart]

I could be way wrong, but my Vox Wah (with mods) was clipping right around the mid travel (the "wah" part) but I likd everything else about the tone, so I figured I would just leave it.  Then I was switching some parts for older "mojo" types (I know, I know... but I just wanted to see if thre was any changes at all).  Every time I exchanged a resistor, I plugged it in and tested it out and noticed no changes.  Then I changed the "box" type caps for old polystyrene caps (pretty much the same values -- I mean within tolerances) and the distortion all but went away.  So could the cap types be responsible?  But as I stated, I could be wrong.  It may just have been slight value changes.
-Joe Hart

[Paul Marossy]

I thought about the caps being a possibility, but I wasn't real sure about that. I would think that it shouldn't matter what type of cap it is. If it's a factor, it's a small one.

Another possibility is that the transistor gain(s) are too low. It's just not amplifying the signal enough and is clipping the signal. In fact, that is the theory I am going with at this point.

Did you socket those transistors? I always do on a wah pedal build for these very reasons.