MXR Blue Box Issue

[rthryhorysak]

I have a blue box I modded for a friend, and I am getting a sizzle noise when the pedal is on. I did the 1/2 octave mod and added a clean boost for more volume. I have since taken out the clean boost to see it that was causing the problem, but it is still occurring. It seems to just be the hum of the guitar because when I turn down the volume on my guitar it will go away. The pedal never did this before because the "gate" function of the pedal seemed to not let it pass. Any thoughts on why this is happening? Thanks

[GGBB]

Sounds like RF noise. Try adding a series resistor on the input ~ 1k.

[rthryhorysak]

Ok I added a 1k and 3.3k resistor in series but there is still noise. I added it to R2, I cant figure out which is the input cap. C1 is a tantalum and the trace from the input seems to go to R2

[GGBB]

Schematic/layout?

[rthryhorysak]

It's an MXR blue box, not a vero or pcb I made. I was just adding mods. R2 is definatley the 150k input resistor.

[GGBB]

"R2" only means something in reference to a schematic or layout. 150k input resistor is a little more helpful, but still only means something in reference to the rest of the circuit. If you could find a schematic for it and provide a link to it you'll be helping the forum offer you assistance.

[rthryhorysak]

I actually just fixed it. The position of the 1/2 octave switch was causing the popping noises. Thanks for your help