Thanks guys....keep 'em coming.
Robert - tried all of those!
Jumper - my PWM pin is in use for other things! (& I want to stay with the PIC I'm using - a 16F690)
Mike - the amp on my circuit is already muted (I didn't explain very well - it's the gain in the guitar amp that is high. The guitar signal feeds into my circuit....which I mute when switching - but this source guitar signal is simply 'Y'ed into my circuit.....the original guitar signal proceeds to the guitar amp as normal - it's this signal that's picking up the LED switching lcick from my circuit.
So the path is like thus....
Guitar pickup 'Y'ed off into two .....
1 ----> into my circuit
2 ----> onwards to the amp as normal (clicking heard on high gain settings from switching in my circuit above)
I need a way of ramping up the led slower so there's no sharp current surge (which is what reckon was causing the pop) - PWM would have been perfect, but like I say, I really want to stick with the 16F690. I have some spare pins left, so it's plausible to do some kind of pseudo PWM.
Toying with the idea of an inductor in series with the led (or possibly bringing a cap into play), just to delay the sharp switch on.
I found this site, but the jury is still out that they've got it wired correctly (I'm pretty sure it's wrong!)...
http://www.muzique.com/lab/led.htm
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