Modify Pedal with optocoupler to Linear potmeter

[match]

Hi,

this is a strange question....maybe.

I have a Vox tonelab SE and want to cut off (really cut off) the pedal section and use these for my guitar modeler.
The thing is, the pedals don't control a potmeter but are optocouplers with a multiplexer etc.
That's great because of no wear, but my modeler needs a linear pot of 100K

Can somebody tell me if its possible to modify the optocoupler signal with some electronics so it will be seen as a 100K pot.....?

Schema of the Vox Tonelab:
http://www.mikrocontroller.net/attac...ice_manual.pdf


Some pictures of the current inside.
https://drive.google.com/folderview?...UE&usp=sharing

882 is the board with the optocouplers. 883 from the sideview
884 the connector near the screwdriver with 3 wires, 2 brown, 1 orange.
885 where those wires go in the direction of the mainboard.
886 the multiplexer? where the optocouplers go to??
887, the signs at the connector.

Further I found in a forum a discussion, where they talk about the parts inside.
http://www.valvetronix.net/forums/ex...ase-t3473.html

I know electronics till some grade, not digital electronics however.

Awaiting your replies with much interest.
Thanks in advance

[Jazz P Bass]

Short & sweet answer.

No. It cannot be done.

[match]

Short & sweet answer.

No. It cannot be done.

Haha, that's short....and really sweet
One cannot make it more clear.

OK, gonna modify it with real 100K pots.
Mechanical, but it works.

Thanks!

[TimmyP1955]

Don't FU the Vox, just buy the proper pedal.

[Jazz P Bass]

Yeah.
That.

[match]

Don't FU the Vox, just buy the proper pedal.

Yep, would do that immediately.....if they would made a 2 pedal board with such a small form factory, lightweight ánd with Vox pedals.
Personally I love the look of Vox, also in their pedals.
But that's me

[Mick Bailey]

You can use optics to replicate a pot but it isn't easy. I experimented successfully to get two LDR/LED setups to replicate a pot's resistance change. One pair transitioned dark to light, while the other went from light to dark and vice-vesa. Set so the mid-point was 50K from either end. I had a sheet of laser transparency stuck to a plastic disk. The graduation of the tint sets the pots curve and end-point resistance. I also had 100K fixed resistors in parallel with each LDR.

Variables are LED colour/brightness, LDR sensitivity and resistance characteristics.

My idea was to get the optimum wah curve and something that I could easily fine-tune. Getting a linear sweep took a lot of time and it would have taken a lot more experimentation to get a successful wah curve.

[match]

You can use optics to replicate a pot but it isn't easy. I experimented successfully to get two LDR/LED setups to replicate a pot's resistance change. One pair transitioned dark to light, while the other went from light to dark and vice-vesa. Set so the mid-point was 50K from either end. I had a sheet of laser transparency stuck to a plastic disk. The graduation of the tint sets the pots curve and end-point resistance. I also had 100K fixed resistors in parallel with each LDR.

Variables are LED colour/brightness, LDR sensitivity and resistance characteristics.

My idea was to get the optimum wah curve and something that I could easily fine-tune. Getting a linear sweep took a lot of time and it would have taken a lot more experimentation to get a successful wah curve.

Thanks for you reply. I have found such a modification on the internet. It was about a game controller but the idea is the same.
It's not the way I want to go. To much trial and error and adjusting problems i foresee.