Popping with BSIAB2

Started by Todd Woolsey, May 01, 2006, 12:01:10 PM

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Todd Woolsey

I've made the BSIAB2 and I have a pretty good "POP" when I click it on. The Pedal itself sounds awesome.  Any thoughts on if I've done something wrong or a fix?
  Thanks a ton,
  Todd.

petemoore

  I *believe that schematic shows pulldown [1 megs?] resistors...so...assuming those are installed and connected...*=I'd check.
  Sometimes mechanical switch noise can be a problem...not often...but there are 'noisy switches'..those'd be the ones that when replaced by other switch, don't exhibit noises as bad when used.
  But also 'BSIAB PoP'...haven't I seen this before a time or two?
 
Convention creates following, following creates convention.

Bucksears

My switch is pop-free, but I don't have a power LED installed yet.
Like Pete said, it could be the switch; do you have another you can try?

- Buck

Todd Woolsey

Thanks for the quick thoughts!
  Pete, I looked carefully at the schematic.  It could be that there aren't pulldown resistors.  If I am correct, the pulldown resistors are supposed to be the first thing the signal hits as it enters the board before the first capacitor and the last thing it hits right after the last capacitor and then the other end of each pulldown resistor to ground. 
  There is a 1M resistor to ground that gets hit after the first 250pf capacitor. Would that act as the pulldown?
  There doesn't appear to be any pulldown resistor at the output of the board.
  Maybe I'll try putting some pulldowns in line.
 
Buck, I do have extra switches I can try.  I'll try the pulldown resistors first and then that.  I do have an LED so I wonder if that could be a factor?  It has a 4.7k resistor in line with it.
 
  Thanks guys,  if you have any other thoughts, keep em coming!!!  I sure do appreciatte them!
  Todd.

Ed G.

It seems like the 'pop' is something inherent to some types of switches. I haven't had problems with hte blue taiwan 3pdt models yet. But I've had carlings that popped pretty well.

Todd Woolsey

Ed,
  You wouldn't happen to be the Ed who's name is on My BSIAB2 Diagram would you?