Velvet Katana Stomp Box

[CJ]

working on a stomp box, supposedly a boutique (reads expensive) type of affair, known for good sound,

build quality?  single strand copper wire that snaps like a dry twig in a stiff desert wind,

so we have to rebuild the whole thing with real wire,

ripped from the Zen Drive we believe,

nice silkscreen,

 

[CJ]

too much coffee, could not grasp pwr circuit, so we do an aux drawing,

 

[CJ]

here is the Zen Drive circuit,

Analog Devices 712

and some 2N7000 fets which function in a way we do not understand, i'm not a transistor guy,  ;D

looks like they are wired as a current source,

DIY?  why not>

http://www.guitarpcb.com/PDF%20Files/Zenith_OverDrive_v2.pdf

 

[CJ]

one more drawing and i'm out...

 

[PRR]

> 2N7000 fets which function in a way we do not understand

Clipping diodes.

MOS-FET is off until Gate goes to maybe 2 Volts, then it turns on.

Grossly, you could use a 2V Zener or a stack of 1N4148s. Some folks feel the "FET has magic", maybe it does.

There is also a trace of asymmetry with different numbers of BAT41 low-threshold diodes.

A bazillion fuzzboxes use the same general plan with every type of diode ever made.

 

[JohnRoberts]

don't over think it... just using the mosfet body diodes as (more expensive) fuzz tone (yawn).  The LED is series with one polarity only, makes it asymmetrical for different flavor THD and adds a light show..

JR

 

[CJ]

thank's guys!  thought the diodes did the clipping,

forgot to add that this thing is made in      Greece.