Remote wah voltage control?

[Sauerkret]

Hello,

I'm building a wah and want it to be remote operated.
I'll be using a VTL5c3/2 how do i generate a controle voltage to manipulate the led in the vactrol?
I only want the potentiometer for the voltage controle in the controller pedal (and an on/off switch )
I hope someone can help. Regards, Eric

[GibsonGM]

Dunno why you'd want to remotely control your wah....doesn't it belong right on the floor in front of you??  But if you did, it's a pretty easy matter of finding a wah shell, putting the right pot in it (100k, maybe? with 'trimmers' to adjust it properly and a limiting resistor for the LED), and using a 1/4" jack and patch cable to connect it to the LED inside the actual wah.  Then use this pedal to control the voltage going to the LED, and voila, remote control...use a switching jack on the wah itself so you can take the remote aspect away when the cable is not plugged in...

[R.G.]

Find Craig Anderton's Wah De-Scratcher article. Run the wires to the wah pot/rocker remotely instead of everthing being inside one shell.

I've done this, it works well.

[Paul Marossy]

Find Craig Anderton's Wah De-Scratcher article. Run the wires to the wah pot/rocker remotely instead of everthing being inside one shell.

I've done this, it works well.

The only problem with that circuit is that I find it to be quite noisy by today's standards.

[R.G.]

The only problem with that circuit is that I find it to be quite noisy by today's standards.

I'm curious. What kind of noise?

[Krefu]

I made a remote wah using the Colorsound inductorless wah with mods and LDR+Led.
I used a 10k pot, supplied by +9V and gnd, with a resistor for the led. And I used a super secret bypass method 

[Paul Marossy]

The only problem with that circuit is that I find it to be quite noisy by today's standards.

I'm curious. What kind of noise?

A lot of HISS. I suppose that it could have been due to an out of spec Harris 3080 IC chip relabeled by NTE.  

When I got my first DOD FX-17, I immediately dumped that Anderton circuit that I put in my Ernie Ball volume pedal because it was WAY noisier. The FX-17 is pretty much totally noise free, even with the highest gain pedals. I also love it because there is no pots to wear out and no pulleys or gears. The only part that moves is the treadle itself. But anyway...

[DiamondDog]

The only problem with that circuit is that I find it to be quite noisy by today's standards.

I'm curious. What kind of noise?

A lot of HISS. I suppose that it could have been due to an out of spec Harris 3080 IC chip relabeled by NTE.  

That's interesting, Paul. I use it with a typical CryBaby-type circuit with a daughterboard with the remote wah bits, a level pot and a choice of caps, (and my own super secret bypass too!) and have no noise issues. I mount my daughterboard (all 2 resistors, an led and a LDR) with the wah PCB on my rack, and run a 3+ strand cable out to a CryBaby copy treadle. All that the treadle has in it is the pot with two caps across it.

You may be right about the CA3080; or could it be the Colorsound just doesn't like being remote-ed? I don't know enough about that circuit.

[R.G.]

A lot of HISS. I suppose that it could have been due to an out of spec Harris 3080 IC chip relabeled by NTE.  

OH. You mean you got noise in a volume pedal, not remoting a wah pot?

[Paul Marossy]

A lot of HISS. I suppose that it could have been due to an out of spec Harris 3080 IC chip relabeled by NTE.  

OH. You mean you got noise in a volume pedal, not remoting a wah pot?

Yes, but isn't the principle the same as the "volume pedal descratcher" circuit? Or would it not add noise in the case of a wah pedal?

[DiamondDog]

You may be right about the CA3080; or could it be the Colorsound just doesn't like being remote-ed? I don't know enough about that circuit.

Sorry, I was assuming that the 3080 was in the Colorsound circuit. I'll shut up now... 

[R.G.]

Yes, but isn't the principle the same as the "volume pedal descratcher" circuit? Or would it not add noise in the case of a wah pedal?

The principle is the same - but the implementation is different.

The volume pedal descratcher changes the gain of an OTA. OTAs have to divide down the signal into them first, then amplify it back up. And OTAs are not particularly quiet anyway. The remote wah sets the current in an LED, which changes the resistance of an LDR, which divides down the feedback signal of a low(ish) gain transistor stage. No noisy OTA involved.

The noise in the volume pedal case is from the OTA, not the wah pot controlling a current.

The devil is always in the details.

[Sauerkret]

thank you all for the input.

[Fender3D]

When I rehoused my pedals in a rack enclosure I made this simple circuit to remote control my wha
(not a real smart circuit, but it works so far):



with just a stereo jack I have the control pot, the bypass switch and an LED.

[Sauerkret]

Hooked up to the R.G. Keen remote switching circuit using a CD4010?

[Paul Marossy]

Yes, but isn't the principle the same as the "volume pedal descratcher" circuit? Or would it not add noise in the case of a wah pedal?

The principle is the same - but the implementation is different.

The volume pedal descratcher changes the gain of an OTA. OTAs have to divide down the signal into them first, then amplify it back up. And OTAs are not particularly quiet anyway. The remote wah sets the current in an LED, which changes the resistance of an LDR, which divides down the feedback signal of a low(ish) gain transistor stage. No noisy OTA involved.

The noise in the volume pedal case is from the OTA, not the wah pot controlling a current.

The devil is always in the details.

Ah, I see. That makes sense now. Yeah, OTAs are kind of noisy when in the signal path. But I guess at the time Anderton designed that, the noise specs were acceptable. A lot has changed since then!  

[Fender3D]

Hooked up to the R.G. Keen remote switching circuit using a CD4010?

lol
I rehoused my pedals in early '80...
no web site to watch to at the time...

I had a DIY switchboard around a 80C31 CPU similar to those Bradshaw stuff....
too bad no Steve Vai in Italy at the time too...

BTW all ( 8 ) pedalboard outs went to relais trough NPNs as for the schematic above.