RM Voodoo-1 vs. Mongoose

[Nick123]

Looking at Justin Philpotts schematic of the Voodoo-1 I see
that there is a lot of similarity with Mongoose fuzz.
In Voodoo schematic  gain pot is probably 10k and
tone and output could be 100k.
At the output of a LM308 after 2.2u is 70k and I believe
that 10k like in Mongoose is better choice.
I  am not sure that values in BMP style tone circuit are good as well.
1.6M is probably 1.8M.
I have never seen that kind of  feedback from output to input.
Could that be some kind of gain reduction ?
Anybody traced a Voodoo or have a verified schematic ?

[MartyMart]

Can you link to Justins schematic, as I dont have it ?
He is usualy accurate in these matters ! so I'd trust the schem.
My understanding is that the RM voodoo is more of a straight overdrive
rather than a "fuzz/distortion" like the mongoose is.

Marty.

[Nick123]

This is the link to schematic :

http://www.geocities.com/j4_student/rmvoodoo.gif

[MartyMart]

Hmm, yes there are similarities, from input to pin 3 op-amp is the same.
Without "pot" values its difficult, but I'm guessing that the gain pot is a 10k and volume 47k  or 100k, tone perhaps 22k/25k.
There are 4 diodes "2X2" followed by the tone section then output.
The resistor across pins 2-6 is different 150k not 100k & 470pf cap.
This will sound different and cause a volume loss too.
My guess ( without hearing one ) is that its a bit less "fuzz" and more "OD" than the mongoose or spitfire.
The tone control will be useful though.
Probably worth building, though wouldn't that "70k" be a 68k ?
and 1.6M be 1.5M .... ?

Marty.

[petemoore]

I think those 'off standard' value resistors would make no discernable [or very little] difference if you rounded the values off to the closest standard ones.