Tone Bender Debugging

Started by zocochico, May 01, 2007, 03:08:52 PM

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zocochico

HI All, I just finished the Boutique Tone Bender from GGG with a set of germanium transistors from small bear. I added a dc/led to the circuit as well. Of course it didn't work right off the bat so I started debugging it with my trusty audio probe. Everything was fine until the emitter of Q2. I soldered it again, swapped around the transistors etc and still no sound from anything after that transistor. After messing with it so much I broke one of the leads off the transistor.

So, I have multiple questions. One is there supposed to be sound after that emitter in the first place? All the others do. And how do I replace a germanium transistor without buy a whole set again?

It is also quite possible that my line of thinking is totally off as I am a bit inexperienced, this is only my 4th pedal and the first one that hasn't worked after my normal debugging.

Thanks for any help.

petemoore

  I don't know which circuit you're building.
  whether there's a FF in Q's 2 and 3 of your TB, in that case, any good candidate for FF Q1...low leakage, gain between say 70 and 150 hfe?
   
Convention creates following, following creates convention.

zocochico

Thanks Pete. I'll have to order a new one then. The emitter should always have sound when you use the audio probe, right? Btw, the circuit is the "Boutique Bender" from the GGG site.

petemoore

Boutique Bender"
  Maybe you're talking about this one ?
  http://www.generalguitargadgets.com/diagrams/tb3bb_sc.gif
  Or one of the other ones...that one has no FF in it.
  at Q2E...you might get 'some' sound, but it's emitter isn't in the signal path, it's collector is, and should be producing a higher amplitude signal than what the base sees or what you'll find in the emitter.
Convention creates following, following creates convention.

zocochico

Yep, thats the circuit. I now see that emitter not in the circuit. Well, it's back to the drawing board... Still learning all this debugging stuff. Thanks for your help Pete.