Input Cap Pop Problems - Any Suggestions?

[muta-exo]

I've built a pretty decent sounding Rangemaster clone based on a few of the usual schematics that have a proven record. I've gone for a switchable input cap option for greater versatility in tone... The caps being 1nF, 680pF & 4.7nF. All in all it's a great little number, certainly sounds like a convincing Rangemaster to my ears. I am pleased with the build except for one thing... The pop this device gives off when the footswitch is engaged is incredibly loud, so loud that I feel the pedal to be quite unusable in a live context. The standard pull down resistor trick in limiting excess current feeding the input caps when bypassed is not proving very successful in this case. I have also changed caps a number of times, therefore I doubt that it's caused by leakage. If anyone has any other suggestions I'd be very grateful.

I intended to give this Rangemaster to a friend as a birthday gift... As it is, with this loud, disruptive pop, I'd be embarrassed to bestow it upon someone.

Many thanks in advance,

K

[ubersam]

did you add an indicator LED? the pop might be related to that. check here: http://www.muzique.com/lab/led.htm

[muta-exo]

I haven't put an indicator LED on this built, not yet anyway. So this can't possibly be the problem either. I will definitely save the article you sent me though for future reference, some good information in there. Thanks for your help.

In the meantime, I'll keep making adjustments... See what I can come up with...

K