A question about the Photon filter wah.

[Denio]

Hi there folks!
So I breadboarded Tim Escobedo's Photon filter wah and it works great.But if I am using it with a distortion pedal(EH Micro metal muff) I  notice that if I put the wah before the distortion,the wah effect is barely noticeable.But if I run it AFTER the dirtbox it is much more pronounced.
So is this normal behavior for this circuit,because I have seen and heard people talk that if you put it before the dist pedal it's more subtle but still there,"vocal-like".

By the way,I am using bc548 in both locations,I think.And I changed the stock red led for a 7mm water-clear,bright blue led.

All help will be appreciated!
Cheers!

[nocentelli]

Most wah designs, and filter effects in general sound much more extreme when placed after a fuzz as they are processing a harmonically rich, clipped and compressed signal.

[Mark Hammer]

In synthesis, people distinguish between "additive" and "subtractive" synthesis.  In the former, harmonics are added, like layers, to create a waveform of this shape or that, depending on how much of various harmonics are added.  In the latter, one starts out with a harmonically rich waveform and essentially "carves away" that harmonic content you don't want, usually with filters.

A wah in front of a distortion is roughly analogous to additive synthesis, since the wah makes some frequencies closer to distorting than others, and adds harmonics in a selective way.  A wah *after* a distortion is fundamentally subtractive synthesis since the wah "carves away" some of the broad harmonic content a distortion produces.

My own experience is similar to your own.  Not just with wahs, but even with pickups and guitar tone controls.  I'm sure many here will say that they've encountered distortions or overdrives that seem completely immune to any changes you make on the guitar, with respect to which pickup/s you're using, or where the tone control is set.  And they've also encountered distortions/overdrives that are pleasingly responsive to changes in tone control settings, and still allow you to be able to clearly identify pickup selection, even when gain on the pedal is cranked.

What allows a distortion pedal to behave the one way or the other is a mystery to me.  But it IS the case that some overdrive pedals sound magical with a wah in front of them and others sound unremarkable or even bad.

[Denio]

Thanks for the answers guys!
Mark Hammer:Well my cheap metal muff isn't really responsive to what's happening at the front end.So you are saying that this whole thing is largely a function of the dirt pedal.
It's not that I don't like the sound with the wah after it,I just would like to have both options,but this will suit me for now.

Thanks again!
Denislav

[Mark Hammer]

It may well be that it is an easy matter - e.g., a buffer stage - to make a dirt pedal respond more to differences in what the guitar feeds it.

I'm with you on the preference to have both A->B and B->A available....or for that matter A in parallel with B sometimes.

[Denio]

A and B in parallel?Aren't there going to be issues with impedance and what not?

[Mark Hammer]

I'm assuming some sort of suitable buffered environment that would permit all of those.  BUt you're right in your response.