a hiss or pop when I plug or unplug

[LightSoundGeometry]

the pedal works great except when I plug the power in or out and its on..kind of freaking me out. is this a grounding issue ? cheap parts? I cant figure it out !

[Mark Hammer]

Below is a DS-1 schematic.  I picked it because it is a ubiquitous pedal, and nicely illustrates several concepts.

The pedal uses electronic switching.  When it is in bypass mode, Q6 and Q7 are turned "off" so the signal can't get to the output via that route.  As well, Q8 is turned "on", so that C2 and C3 get connected pretty much directly.  BUt the impoprtant point is that "bypassing" the effect takes place internal to the circuit board, and not outside it.  What that also means is that the input and output of the pedal will NEVER be disconnected unless:
a) you plug/unplug, or
b) the pedal is preceded by another pedal that uses true bypass (which will momentarily disconnect the input of the next pedal in line as the preceding pedal switches from taking the output of the circuit board to taking its output from the input jack).

Now, look at the input of the DS-1, and you'll see that C1/R1 will never have any way to drain off to ground UNTIL something is plugged in to the pedal that provides a path to ground.  If, just for illustration, that happened to be another DS-1 (now THAT's distortion!), R23 would provide that drain-off path, once the two pedals were connected.

When there is no constant path for that input cap C1 to drain off, you will often hear a pop when you plug in, or a pop when you engage/bypass a true bypass pedal immediately before it.  The pop is the stored current in C1 finally have a path to drain off.  When it all drains off at once, you hearthat as a pop.

I say "often hear", because there may be stored current, or there might not be.  Stick a TB pedal in front of somethng configured like a DS-1, and if you use its stompswitch repeatedly in short period (on-off-on-off-on-off), the pops will disappear, because the stored current has drained off.

The "solution", if you want one, is to simply connect a resistor, in the range of 1M-2M2, or so, between R1, and ground.  That's it.  There is a teensy amount of loading of the input, as a result, but not anything you'd notice with a guitar signal.

Make sense?

[LightSoundGeometry]

wow, you are exactly right. it comes and goes, and i was thinking from a stored cap somehow. and yes, I do see r1 and c1 nor draining to ground. makes perfect sense . I am still new, learning how to breadboard so the flow is still somewhat confusing with a larger schematic like this lol. i was trying to follow the signal path on the vero layout I cloned. I can see input going to c1 55n and looks like a 1m to ground

http://tagboardeffects.blogspot.com/2012/02/lovepedal-eternity.html

I am still having a hard time going from BB to vero ..not worried about vero anymore, I want to learn the signal path and how each part works first then move it over later down the line. I am working on the LPB1 and a few others from beavis. i wish schematics could be broken into pieces and connected, I get lost when several parts start combining and crossing each other even on basic ones still.

appreciate the feedback, at least I know the pedal is working right