I have built the Quasar several times on Madbean pcb pattern, using RC values. Also have done the AC/RC on vero. On the PCB versions I had a strange crackle or pop on the treble control. BOth times. And even after swapping out pots several times. The one I have now has two loud "pops", both close to the counter-clockwise extreme. I have swapped the pots out (alpha, 50k linear) and the replacements do the exact same thing in the same place!
The earlier version got a nasty distortion on this same point in the pot travel, a sudden extreme fizziness that went away after I subbed the pots. The new circuit had the fizz on the first pot, just the pop on the second and third.
Any ideas? Whole baggy of pots with identical defect? I took one apart and there is no visible damage, no huge splash of solder or anything.
The earlier version got a nasty distortion on this same point in the pot travel, a sudden extreme fizziness that went away after I subbed the pots. The new circuit had the fizz on the first pot, just the pop on the second and third.
Any ideas? Whole baggy of pots with identical defect? I took one apart and there is no visible damage, no huge splash of solder or anything.