CHRISTIAN HOLMBERG (HEMMO): Bazz Fuss, Tag Board & Vero Layouts

This is a nice easy one for tag board off-cuts.  The Christian Holmberg (AKA Hemmo) Bazz Fuss.   

A simple one transistor monster of a fuzz.  Kind of surprised that I had not done a layout or actually built one of these...  how did this not happen earlier?  I was prompted to do this after browsing on Ditrbox Layouts and saw the Walrus Audio Contraband fuzz - link here which is a Bazz Fuss with an input cap switch. 

So here it is.  Will probably post a couple of other versions for 0.15" and the standard vero later.  Being such a simple circuit, it's ripe for modding and component value tweaks.  

Mods (Which are almost every part on the board):

• size of the input and output caps (input cap most critical)

• type of diode used between the bass and collector of the transistor

• the transistor itself (NPN silicon)

CHRISTIAN HOLMBERG (HEMMO) BAZZ FUSS - TAG BOARD LAYOUT 

0.15" VERO LAYOUT 

STANDARD VERO LAYOUT 

BAZZ FUSS ON LTSPICE

I haven't shown changes in diodes and transistors below, as while they might sound different (I'm yet to test this myself), they don't appear all that different on LTspice.  The waveforms are quite similar, with variations in level and minor variations in shape.

For me, the key driver of changes in this circuit appears to be the input cap.

Volume on 50% - not quite a square wave, but most of the way there.

With a 4.7u input cap and a 100n output cap the frequency response is almost flat - note the db scale (volume at 50%). 

Change the input cap value, and things start to happen with the response 

BAZZ FUSS - VIDEO DEMO

I've used the Walrus Audio Contraband Fuzz as a demo, as it's the best demo I could find of a Bazz Fuss circuit, even though it isn't strictly a stock circuit.   

The only significant difference is the input cap switch, which handily demonstrates the differences when changing C1.   220n and 33n are the values used on the Contraband.