I looked at his logic and felt stupid. Everything the cap does in a guitar and pedal goes right out the ground wire to tone heaven somewhere. I thought "why in the hell did I spend this money on my pedals Mr. Robert Keeley"?!

It was posted paper in oil caps are more expensive at about $4 each, but well worth the extra money in tone. I stated that ceramic caps sound terriible. In retrospect, I believe the tiime I noticed that huge difference was in the amp and not the guitar. So, I'm an idiot.
Being an idiot, I decided to experiment with one of my pedals to see if different type caps sounded different at all. Being a brilliant scientist, I didn't choose just any pedal, no sir. I got my vintage OD-1 out. So, I looked into my magical grab bag of capacitors to see what I had that would match values. Sure enough, I had .047's in oil and ceramic to try out in the first stage. It has a mylar or poly or whatever the hell it is in it already.
My man Mike at the ready with guitar in hand, we tried the OD-1 pedal stock, then tried the other two caps playing the exact same riffs and same settings each time. I did this several times mixing up the caps so he couldn't cheat. I asked if he heard anything different. He said no and I agreed as I heard no difference at all. So, I tricked him and put in an .022. Yep, difference for sure.
Now I wanna take all my pedals apart, especially the boutique ones to find out what's in there. My Keeley BD-2 does sound different from stock for sure with the Phat switch. Robert told me why when I bought it from him at the Dallas show but I don't remember the details.
Finally, I Googled prices. Holy smokes, the PIO cap for the .047uF value was between $14 and $20!! Nope. Orange Drops for everybody on me!! Yay!
Being a brilliant scientist, next week I think I'll take apart my grandmother's old antique clock.
Have some fun today,
Zippy