i'm looking to build a wah using an LDR for the control since i have the empty shell including the expression pedal section of a zoom GFX-5 laying around and i need to either use it or throw it away. can anyone recommend a good wah projectand how to sub in a LDR for the wah pot? or even any effect thatwould benefit from a foot control where i might be able to integrate it. thanks in advance!!!

Not a Geofex reader, I see.

Try "The Technology of Wah Pedals" in the "Technology of ..." section at GEO, http://www.geofex.com

If you don't want to modify a normal wah to use an LDR then you could try one of these from Tim Escobedo's site.

http://www.geocities.com/tpe123/folkurban/fuzz/photonfilter.gif this is a wah that is designed to use an LDR.

http://www.geocities.com/tpe123/folkurban/fuzz/idiotwah.gif here's another one that can use an LDR.

Quote from: R.G. on November 29, 2006, 12:06:56 PM
Not a Geofex reader, I see.

Try "The Technology of Wah Pedals" in the "Technology of ..." section at GEO, http://www.geofex.com

RG, will you give us more advices on how did ya do the switching? c'mon dude, reveal your secrets

No secrets involved. Do you mean how did I do the bypass switching or how did I switch the circuit around?

Quote from: R.G. on November 29, 2006, 01:34:35 PM
No secrets involved. Do you mean how did I do the bypass switching or how did I switch the circuit around?

both. cos i wanna do the same thing but theswitching is killing me. i need to do with one conector, so i thought bout TOne God, but im not too convinced bout it. did ya used a relay?

OK, I must be short on coffee today.

Do you mean that you want to plug the expression pedal into another box that has a wah circuit already in it?
And that there is a working wah circuit inside the other box, so that when you plug in the expression pedal, the expression pedal pot takes over?
And that there is an LDR inside the other box wah circuit that does the actual wah-ing so that you don't have to run the audio out to the expression pedal and back?

If so:
1. Build a standard Vox style inductor wah. Replace the wah pot with a 100K resistor and the LDR of an LDR/LED module, just as in Craig Anderton's "Mod your Wah Pedal" article. The illustration in the article shows what circuit mods to make.
2. Hook the LED current control per Anderton's article to a 100K pot inside the box, but route the hot and wiper contacts through a stereo closed contact 1/4" phone jack on the side of the box, and wire the interior pot to the normally closed contacts on the jack. Wire the +V connection to the signal contact on the jack whose normally closed contact connects to the hot lug of the in-box pot, the LED control to the signal contact that connects to the normally closed contact that hits the wiper of the in-box pot. Wire the expression pedal to a similar jack in the expression pedal box, making sure that the hot and wiper go to the same signal contacts (that is, tip and ring) as the pot in the circuit box does. Ground is the sleeve on both jacks.

Now you plug in a stereo cable on stereo 1/4" plugs to both jacks. The plug opens the normally closed contacts and inserts the remote expression pot into the circuit. When you pull the plug, the in-box pot is reconnected by the normally closed contacts on the jack.

Better? The secret is two stereo 1/4" phone jacks and a stereo phone cord.

but how u bypass it? i think im missing somthing (english is not my language). the led thing is ok. i got it. but how u can bypass it?

RG, with all respect (cuz u deserve a lot, your website is amazing) i think its time for you to update ur "The Technology of Wah Pedals).
in the section "What Affects What? - or - What Do I Change to Make It Do (whatever)?" u havent write nothing 'bout Rfb (usually noted a Mid boost, midrange or saturation pot) nor Cout and Cef. those values changes from one wah to another (between .001 or .22uF). Anything special bout these caps?

the best wah i can recomend, is the Colorsound Inductorless Wah, must be the nicest i've ever heard

Quote from: nordine on November 29, 2006, 08:10:30 PM
the best wah i can recomend, is the Colorsound Inductorless Wah, must be the nicest i've ever heard

what's so fancy about 'em? u have any clip? i'd love to hear it, cos i want a gutural vomit-like sound (i love the 535Q) with some help, i'll finish my schematic tomorrow, a crossover between the 535Q (or the Dime wah), morley sweep style (or RG LDR-100k style) and GGG Modable Wah. plus, i'm think about a dual 4066 Capacitor Switcher, wich is an 8-way rotary switch. i can have em so easily, but i cant find em in double pole version, so i've had to try a circuit based on Laurier's.

Laurier: http://members.shaw.ca/roma/switching-2.html
Andrew: http://www.geocities.com/thetonegod/
Morley: http://www.morleypedals.com/pwonewes.pdf

For some reason, i refuse to use a 4053, 4066 or JFET style switching. I want true bypass, so i was thinkin' bout using a relay.

Of course, all of this will be in a rackmount unit (so i can use an adaptor).

*If ya' check the Laurier switcher, it seems u can use it to change the capacitors (the stock 10n) using just a button. If you adapt Laurier's thingy, you can use only 4 values (10n, 15n, 22n, 33n, i dunno, use your imagination...) BTW, i'll use that switchin' system with LED indicators (my rackmount unit -huh huh huh, i said unit huh huh huh- will have a lot of shiny things  )

My only trouble is the bypass thing
How you did that, RG?

i was thinking, i could wire this as a variable resistor in place of a pot on a booster to act as a kind of active volume pedal with a foot control. the pedal just has a flat piece of metal whose distance from the LDR varies as you  move the pedal. could i wire this between the board output and the output jack as a volume control?

Quote from: R.G. on November 29, 2006, 02:03:09 PM
just as in Craig Anderton's "Mod your Wah Pedal" article.

Where can one find this article?

QuoteMy only trouble is the bypass thing How you did that, RG?

The bypass is back on the box, not on the rocker pedal.

If you want the bypass on the pedal, you are out of wires in a phone plug style cord. You'll have to run at least one more wire out to the pedal. I recommend running a relay or CMOS switching back in the box, and using something like a mini-DIN connector with five or six contacts so you can use two wires if you control a relay back in the box.

QuoteFor some reason, i refuse to use a 4053, 4066 or JFET style switching. I want true bypass, so i was thinkin' bout using a relay.

What reason is that?