Wah Inside My Guitar Project

[Paul Marossy]

After some discussions about Zappa and his identical dual onboard but seperately voiced parametric EQs, I thought it might be kind of cool to have on onboard wah circuit built into my guitar. I got the idea after recntly listening to Zappa's "Shut Up and Play Yer Guitar" 3 CD set. A lot of his guitar tones sound to me like a wah pedal kept at a static setting - kind of like that Dunlop Q-Zone pedal. I figure that I'll use it as an adjustable resonant filter kind of thing.

So, I decided to take my Maestro Boomerang BG-1 layout and make it as small as possible to get it to fit inside of my Frankenstrat's control cavity. Got the PCB down to 1-3/4"x1-9/16" and it just fits in there. I'm working on making the finish on the guitar body a little bit better, so while I have the guitar apart, I figured it would be a good time to implement my idea. I've got it all rewired and in a week or so when the finish is all cured, I'll pop it into the guitar and take it for a test drive. I'll post some pictures later.

Here's the PCB layout for anyone who might be interested: http://www.diyguitarist.com/PDF_Files/BG-1Compact.pdf  - it's set up for a Fasel or the inductor found in current manufacture CryBabys.

[tcobretti]

That's a cool idea.  I'm not a Zappa fan (just never really got into his stuff, but Willie the Pimp is awesome), but I've always thought he sounded like he was playing thru a static wah. 

What do you play, a strat?

[Paul Marossy]

What do you play, a strat?

My main guitar is a Parker Mojo Nitefly, but I also have a couple of Ibanez guitars and Strat that I "modified". 

[tcobretti]

That's the best thing about strats: I never feel guilty modding 'em.  Changing something on one of my Gibsons feels like painting clothes on Michaelangelo's Last Judgment.  But for some reason, a strat is always just a strat.

[Paul Marossy]

But for some reason, a strat is always just a strat.

Yeah, you can change out a pickguard easily. Filling in holes in a Les Paul is another story, however. 

[jonathan perez]

what about just using a colorsound inductorless?

[Paul Marossy]

what about just using a colorsound inductorless?

Not resonant enough for me, but that's also an alternative. It could be made into a pretty small PCB. 

[lacto]

Cool idea. Looking forward to your reports on it...

[jonathan perez]

come to think of it, Tom Morello has a guitar, ibanez 335 style, with an onboard wah, Whammy, and treble/bass boost.

but then again, its hollow...

[R.G.]

I might be tempted to do a state variable filter using an LM13700. You can get any Q from under 1 up to self oscillation, plus any gain you like.

I think a dual opamp and an NJM13700 would do this. Frankly, if you could get a dual trimmer to set the frequency, two dual opamps would do it.

[Paul Marossy]

I might be tempted to do a state variable filter using an LM13700. You can get any Q from under 1 up to self oscillation, plus any gain you like.

That could be pretty cool.

I think a dual opamp and an NJM13700 would do this. Frankly, if you could get a dual trimmer to set the frequency, two dual opamps would do it.

I was thinking a few months ago that the Tychobrahe Parapedal with individually adjustable pots might come close to acheiving what Zappa had in his guitars, but I don't know for sure. That might be the next thing I try, just to satisfy my own curiousity.

[Paul Marossy]

Well, it worked straight away, so I'm happy about that. Sounds pretty cool in this particular guitar, too. OK, here's some pics. It's kind of hard to see, but the PCB is attached to "wiring harness" with some zip ties. The black stuff is some 1/16" thick self-adhesive foam rubber stuff that I got at the craft section at Walmart. It's there to prevent shorts to ground in my fully shielded control cavity. The control knob is an after thought, of course. When I make my aluminum pickguard someday, I will adjust the holes and stuff. The blue switch is for bypassing the wah circuit.

[tcobretti]

I really like it.  I think it's cool that it doesn't have a knob - makes it easier to set and forget.

[Paul Marossy]

I really like it.  I think it's cool that it doesn't have a knob - makes it easier to set and forget.

Yeah, I like that, too. You can't accidently move it - it takes a deliberate effort to change the setting. 

[petemoore]

you can change out a pickguard easily. Thanks Leo!
  Looks like...do you have a 2 piece pickguard, even better !
  One tight looking cram from side to side! Chok about full of guts, you did well to get that in and have it work right off I think...kudos are in order...and...how's it working out for the Zappa thang?
 

[Paul Marossy]

how's it working out for the Zappa thang?

It sounds similar and it has the same general feel, but I think not quite as "complex" sounding as Zappa's EQ circuit(s).

[lacto]

Sounds like a cool project. There is no room for anything like that in a Les Paul control cavity...

[Paul Marossy]

There is no room for anything like that in a Les Paul control cavity...

There isn't? I thought there was at least as much room inside a Les Paul control cavity as there would be in a Strat. It's been a long time since I've worked on a Les Paul type guitar, though...

[petemoore]

how's it working out for the Zappa thang?

It sounds similar and it has the same general feel, but I think not quite as "complex" sounding as Zappa's EQ circuit(s).

We saw the man at Richfield Coliseum in '76, other than all the really cool songs, amazing band play, and blow up love dolls, my favorite part of the show was when Frank and the Percussionist took 15 to lay some very '1 on 1' heavy jamms down...Looked like he had at least one jamm packed rack unit and some floor stompers to work with alot of other 'stuff'.

[lacto]

I should have said in "my" Les Paul control cavities. I have two push/pull pots which take up most of the extra depth. With a stock wired LP, you are probably right that there would be room for a small circuit board...