Colorsound One Knob Fuzz

[brianwenz]

Hello Hello--
       Anybody built this one???    There seems to be a problem with some of the res. values and was wondering if anybody got it up an running.
Brian.

[MartyMart]

Hi Brian, have not seen you here for a while !
I built the Drangonfly vero version, it's in his layout gallery, works a charm
all his r values seem correct, I used a 108/109 as specified.

MM.

[brianwenz]

Hello Hello--
      Hi Marty.....yeah, I've been pretty busy fixing guitars......I posted a few times around here lately, though.
  Did you use original 108 and 109's  or are they newer versions??     I've seen so many different hfe readings on those trannys that I got confused as to which is the "correct" gain.
Brian.

[smnm]

...in the FuzzCentral is back thread, Philip Bryant mentions an amended schematic traced by Stuart Castledine newly uploaded at FC:
http://fuzzcentral.ssguitar.com/schematics/oneknobfuzz.gif

FWIW it's not really a 'vintage' pedal at all - it was designed in the '60s by Vox guy Dick Denney, but not put into production until relativley recently. Could be they just tweaked the resistors a bit over the production run.

[MartyMart]

Mine was built with an 820r not an 82r and works great ?
108/109's are newer from Ebay parts shop.

MM.

[JHS]

Got mine to work too, used a 820E and the sound is very good too with a high output. With a 82E it was gated and total useless.
Does not like trannies with high hfe, the result was overcompressed mud but 108B/109B with low to medium hfe work fine in this circuit.
Works too with Ge or Si trannies with low hfe, but then it sounds very undefined and woofy, kinda like a bad FF.

I recommend to use a 1k trimpot for the 820E and a 22k trimpot instead the 10k on Q1, makes setting up the Fuzz a bit easier, I had to swap some 108/109 in and out until the sound was good.

The additional 100uF fiter cap produce some more highs and a stiffer bass when compared to the original design, but I like the added crunch.

BTW: there are some variations in the values on the original units, seems that the Rs had been addapted for the trannies acc. to the specs of the lot.

JHS

[Hepcat]

I built a couple of these a few weeks ago really cool pedal , and fun project.!  --J--

[phillip]

It's confirmed guys...the resistor is 82 ohms, not 820.  Stuart emailed me and said that the resistor measured 81.7 ohms and the voltage on Q2's collector was 7.02V.  It was just misread the first time as being 820 ohms instead of the correct 82 ohms.



The 820 ohm resistor will make it louder, though...that's never a bad thing

Phillip

[brianwenz]

Hello Hello--
      Phillip-- Thanks for the pic!   I can't help thinking that maybe the 82 ohm was a replacement........! 
Is that a Colorsound board??
I need to ask Stuart who really shot Kennedy......................!
Brian.

[phillip]

Yep, that's an all-original Colorsound one-knob perfboard.  No replacement parts in the circuit.

As for Kennedy...I strongly suspect that Lyndon Johnson had a lot to do with it

Phillip