Help using Simple PCV fader as a sound kutter (VCA?)

I want to use a PCV Vestax fader as an audio kutter inline with an audio signal. I tried hoking the audio up through it and it it has a very gradual fade. I need it to be as sharp as possible. I want it to be at full volume as close to the edge of the throw *** possible (1-2mm away from off).

So, Im thinking I need to use a VCA to achieve this effect (I can then either tape over the carbon tracks or scrape them) or if im using an alternate optical "fader" that really only acts as a switch (Focus Fader V1 FFV.1)

I have attached pictures of both types of faders I could use. The PCV fader has had 2 of the 4 carbon tracks scraped to give a sharp kutt in for 1 channel (vestax 05pro2 VCA mixer)

focus fader


Vestax PCV fader



I reverse engineered that focus fader and built my own PCB for it and used Optek Technologies OPB620 optical interrupters for the switches, however I can only use it in my mixer, and I want to use it just as a simple audio kutter... this birngs me to you guys, to see if you can exercise any genius on this one..

Below is the DIY optical fader PCV (of course thats just the electronics not the physical fader slide)




Any and all help greatly apprecciated,
Mike

is anybody even familiar with this type of thing?

I figured it out, heres the circuit for anyone interested in building one.
You will need a fader with a 50k resistance... Or you can use the schematic I provided above to make your own optical "fader" switch

This is mainly for DJ use, but is a good thing to know.

heres the pic




Many thanks to Elliot (Emarx) of AudioInnovate for posting this through the www.skratchlounge.com forum.... (mods sections)