This construction is based on Mark Hammer's Tube Fuzz Sound Adapter
which in turn was inspired by Craig Andertons Tube Fuzz

Mark's idea not creating distortion within the 4049's cmos stage's appealed to me!
Just letting an external op-amp do the job. Very good idea indeed!
Only the first cmos stage has some gain though!
My idea is to ad two more stages to the basic unit to get more distortion(there are 6 amps in the 4049)
Then i trimmed the op-amp's gain with my guitar until no distortion was heard
This is important because otherwise the bass strings will sound muddy and dull
Because of the four stages the distortion has a more harmonic nature
and to me it sounds very good! This effect also works very good together with
the guitar volume. Nice sustain!
I must say that there is an interesting clean sound obtainable by using only two stages!
I was suprised by it because it sounded so good, a fat clean sound!

Sound:
In the wav file i use my stratocaster, starting with the tone in the most treble position,
using my bridge mike.
While playing i turn down the tone completely. Gain and drive turned up to 2/3. No boost!

Modifications:
A pot to control the op-amp's level with.
Of course we can change and alter the resistor values
around 4049's circuitry will create more or less distortion.
Changing the caps around the 4049 inflicts the sound.(470pf, 4.7nf caps)
Bigger caps will reduce more treble and smaller will let more getting through

It's easy creating a two channel fuzz!
Remember there are six(6) gain cells in the 4049! Using two circuits for channel 1
clean to overdrive type of dist and four for channel 2, moderate to heavy dist
Two parallel gain pots after the op-amp, drive pot(channel 2) and two level pot's
at the output selectable with a DPST footswitch and maybe a tone circuit
thrown in there(channel 2) and we have a very smooth fuzz!
A simpler method is to switch the two last circuits in when a lead fuzz is needed!

Stellan