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DIY Stompboxes => Building your own stompbox => Topic started by: LucifersTrip on September 26, 2010, 05:17:17 PM

Title: Fuzz-Rite: beginner warning, bad schematic
Post by: LucifersTrip on September 26, 2010, 05:17:17 PM
Here's a warning for beginners...

A couple years ago, when I first had the desire to clone a pedal, I had zero luck...
I couldn't afford a vintage fuzzrite and it was always my favorite type sound so I did the typical Google search and found
this  schematic at one of the big sites, schematicheaven:
http://www.schematicheaven.com/effects/mosrite_fuzrite.pdf

...in a section called "Effects Heaven"
http://www.schematicheaven.com/effects.htm

I built it with my father, who actually built transistors in a lab in the late 50's - early 60's. I used all components that he saved from then...
...and got no sound at all.  We double-checked and triple checked all values, connections, etc and finally gave up & threw the dead circuit in a box.

Two or three years later, I started circuit bending a bunch of toys and shortly after got the bug for some fuzzes again. I decide to to the fuzzrite again, but a new Google search gave me this:
http://fuzzcentral.ssguitar.com/schematics/fuzzriteschem.gif

The Effects Hell site has the tip of the input jack going to the negative of the battery and the casing going to the .05 input cap.
The input is reversed! In addition, the 350K pot is shown as 350.  Both critical errors.  I also couldn't find TZ82 anywhere so we picked  random transistors from my father's stock, which turned out to have an hfe of less than 20.

After building 15-20 fuzzes, I remembered I had this dead one one stored away. I pulled it out, made the corrections and got that killer
fuzz right off.

Bottom line, when you're first starting, always get a second opinion.




Title: Re: Fuzz-Rite: beginner warning, bad schematic
Post by: LucifersTrip on September 28, 2010, 04:46:39 PM
Ironically, the 2nd schematic I built [Op Amp Muff Fuzz] also had the input jack reversed:

http://www.montagar.com/~patj/mufffuzz.gif
Title: Re: Fuzz-Rite: beginner warning, bad schematic
Post by: albertozioli on December 14, 2010, 08:46:25 PM
Guys I'm trying for ages build my fuzzrite clone and I have some problems, could you guys give me a hand, I'm talking to other guy on the mosrite forum, he is tring to help me as well, this is the link has some pictures of the project there...

http://www.mosriteforum.com/forum/viewtopic.php?f=20&t=3807

Cheers!
Albert
Title: Re: Fuzz-Rite: beginner warning, bad schematic
Post by: PRR on December 15, 2010, 01:19:01 AM
> I'm trying for ages build my fuzzrite clone and I have some problems

Rather than tag-on to EVERY old FuzzRite thread you can find, please read this:

DEBUGGING - What to do when it doesn't work (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0)
Title: Re: Fuzz-Rite: beginner warning, bad schematic
Post by: Barcode80 on December 15, 2010, 01:22:29 AM
There is a thread here with a CORRECTED fuzzrite schem, so far none of the sites you can find it on until then had it correct. I believe it was one resistor value...
Title: Re: Fuzz-Rite: beginner warning, bad schematic
Post by: LucifersTrip on December 15, 2010, 01:28:55 AM
I posted a correct one above

(http://fuzzcentral.ssguitar.com/schematics/fuzzriteschem.gif)
Title: Re: Fuzz-Rite: beginner warning, bad schematic
Post by: petemoore on December 15, 2010, 06:22:11 AM
  The audio probe, the voltage measureing device, apply debugging to see the transistors provide useful into.
  I had trouble establishing signal passing bias with 470k collector resistors, 10x smaller allowed signal through. Perhaps the large collector resistors support bias better with lowish Hfe transistors?