Weird power thing with Rebote. Not really a problem, but just curious why...

[studiostud]

Hello,

I built a rebote 2.5 from the tonepad layout and also added an IC buffer (from GGG) in front of the 3PDT to make it a buffered bypass.  When I plug the +9v power supply into it and activate with the bypass switch, there is a strong switch pop that gets repeated with the delay circuit.  I noticed that if I leave the pedal plugged in, the popping gets softer and eventually goes away after a few minutes.  So I broke out the multimeter and traced the leaked DC voltage to the buffer's electrolytic cap.  the positive side is getting ~3.3v from the TL072 and the negative side, when power is first plugged in, registers about 0.45v and then slowly decreases down to 0v. Since the IC buffer doesn't have a pulldown resistor on the output cap, I tried a 2.2M resistor on both the + and - side of the electro to ground with no effect on either circumstance.  I also tried swapping the electro and the TL072 with no difference shown.

It's not a huge deal at this point as long as I don't have to plug it in and then immediately start playing within 90 sec.  I was just curious in case I end up making another one in the future for someone else.