Muff Fuzz learning curve

[greenacarina]

I finally got the correct IC in my Muff Fuzz build (DIP instead of SIP) and IT WORKS!! WOWEE!
Here is the layout I'm using- http://aronnelson.com/gallery/album17/EH_MUFF_FUZZ
The problem I'm running into now, I can play through it just fine but it only repsonds to a fairly strong vibration from the strings. I can strum a chord and get a really cool octavey sounding fuzz, bu as the strings' vibrations die away the sound drops off sharply to kind of a "fizzle". I'm sure there are more technical terms for all of this, but I'm still wet behind the ears. This seems like a pretty simple circuit and I'm hoping someone can explain the theory of what the components are doing. Maybe something is working incorrectly, or maybe I need to change the value of something to get a more desirable effect?
Thanks!!
Chris

[petemoore]

I can play through it just fine but it only repsonds to a fairly strong vibration from the strings. I can strum a chord and get a really cool octavey sounding fuzz, bu as the strings' vibrations die away the sound drops off sharply to kind of a "fizzle". I'm sure there are more technical terms for all of this,
  This sounds like a description of 'gating' being caused by a misbiased opamp...voltage measurements will confirm/disprove.
  hoping someone can explain the theory of what the components are doing.
  well..I could..but you're wayy better off going into FAQ and linking around...also in Links.
 

[greenacarina]

I can play through it just fine but it only repsonds to a fairly strong vibration from the strings. I can strum a chord and get a really cool octavey sounding fuzz, bu as the strings' vibrations die away the sound drops off sharply to kind of a "fizzle". I'm sure there are more technical terms for all of this,
  This sounds like a description of 'gating' being caused by a misbiased opamp...voltage measurements will confirm/disprove.
  hoping someone can explain the theory of what the components are doing.
  well..I could..but you're wayy better off going into FAQ and linking around...also in Links.
 

OK, my battery voltage is 8.47
IC voltage at each pin-

1- 4.67
2- 4.30
3- 4.15
4- 0
5- 4.20
6- 4.30
7- 4.26
8-  8.43

I will study up on some of the links and see what I can learn.
Thanks for the help!!
Chris

[petemoore]

1- 4.67
2- 4.30
3- 4.15
4- 0
5- 4.20
6- 4.30
7- 4.26
8-  8.43
  Well...these voltages...actually look pretty good!...that's bad tho, I thought there would be an obvious misbiased pin...pin1 is 4.67v of 8.47v...{I'm not too good at math, looks just outside the +/- 10% tolerance rating]...pretty close to 1/2, and should have room to swing _/+ with source input...hmmm...probably not the problem, perhaps it's supposed to be not exactly 1/2v there...
  Description still sounds like gating...so I'm at a loss for further response right now...hmmm...anyone else? Wierd because misbias would do exactly what you described, and I don't see a 'culprit' pin voltage measurement...I would say try it again and make sure the voltages don't change between trying it and measureing it...leave it connected to the amp so that you don't 'jostle' it while measureing...those voltages ring of a working opamp to me.

[Dragonfly]

Try putting a resistor "parallel" to the clipping diodes...probably anywhere from 470k - 1 meg.

AC

[Meanderthal]

 Yes, it's gated all right. Apparently this is by design. Mine does the same thing... I had brought this up on another thread, and there is a mod to fix it- possibly what Dragonfly posted.

[Gus]

In schematics section
http://www.diystompboxes.com/pedals/mfuzz.gif

[Meanderthal]

 Thanks Gus! That's the one!

[greenacarina]

Try putting a resistor "parallel" to the clipping diodes...probably anywhere from 470k - 1 meg.

AC

That did the trick!! I may have to build this one again, though and try out some of the other mods that Gus suggested.
When I read "insert switch here for fun!"....how can I resist???