Rangemaster operating problem

[BD13UK]

I built the Rangemaster from Torchy's veroboard layout, I fitted a 3 position minitoggle to use as a cap switcher from 0.0047/ 0.47/0.1 however when using the 0.0047 position theres no problem it works great but when switched to either of the other options although it works the guitar volume control scratches real bad and I've tried it with three different guitars !!!!!! any input would be most appreciated.

[R.G.]

You're getting DC back out of the input of the rangemaster.

Scratchy pots almost always have DC on them. Your rangemaster is feeding it back into the guitar.

[BD13UK]

Thanks RG, having scoured this and the Geo site I cant find an explanation with regard to a solution, as the guitar pots seem to be fine on all settings other than the aforementioned I wondered if the inclusion of a specific value cap and or resistor from input to ground of the Rangemaster would rectify the problem ? I dont encounter this problem with the rest of my gear which leads me to assume  as you suggest that it's all down to the Rangemaster and only certain frequences create the problem, of course this is pure speculation from an amateur perspective.

[R.G.]

Turn your rangemaster on, plug in the cord from your guitar, and measure DC volts across the input jack from tip to sleeve.

It's likely that you have a solder short or a wiring error.

If you don't find it there, it could be coming from some other pedal. Track it down with a voltmeter.