Looking for the right Fuzz Face PCB and a couple questions

Started by aab0mb, April 22, 2019, 12:28:17 PM

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aab0mb

Schems for reference: http://www.geofex.com/article_folders/fuzzface/fftech3.gif
                                 https://www.diystompboxes.com/analogalchemy/sch/antiquity.gif


I've come to join the church of fuzz after many years. I gotta say, FEELS GOOD MAN!

I'm interested in versatile tools so i'm building this particular NPN silicon FF with a focus on a wide range of sounds.

I'd like to implement the "smooth" pot at the input along with the bass blend knob and possibly the input diode ala Antiquity fuzz.

Bias is a nice option and of course the fuzz and volume knobs.

SO, we're at bass control, input control, fuzz control, volume, and bias controls so far. That's 5 control and i'm hoping to squeeze this thing into a 1590b. Trim pots aren't out of the question but i'm struggling to choose which control to NOT have mounted on the outside of the pedal. While breadboarding, i found that i could still get a good range of sounds with the fuzz maxed and using the input and bass knobs to control fuzz/gain/voice.

I'd like to etch a PCB for this but there are a lot of options out there and I've yet to see a pattern which would help me implement all these options smoothly.

Do any of you gentle-persons know of a good fuzz face PCB for modding off the top of your heads? I'm aware that i could chain components together and stand them up, etc, but i'd like to make a very tidy build if possible. 

Also, the Antiquity fuzz diode which limits the input to the forward voltage of the diode in order to stop the first transistor from clipping, does the input "gain" pot function at all similarly and would it be a virtue to keep both options or? 

Thanks for reading and taking the time with any replies!

aab0mb



So this is my first attempt at layout creation. Hopefully once this is finished it'll have some value or usefulness to someone besides me!  :)

This is the basic topology I've been mulling over. It's kind of a mashup of fuzz circuits and common mods. The board is etched, and mostly working... I'll have to go back and clean up the layout, part numbering and add values etc etc

The extra holes in the PCB are to add potential mods should a person need locations/anchor points.

There are a couple quirks that i've run into with the Fuzz/bias control combo. As it sits, the fuzz control is a 2k linear pot with 22uf cap to ground and the bias control is a 10k linear.  I'm anticipating halving both of the mentioned pot values because as it sits, lowering the fuzz control cuts off the signal at a certain point.

I'm aware there are a lot of interactions to this circuit so I've been reading up and learning a ton. Hoping to work out the kinks and get this thing boxed up and looking official!

Would low gain transistors (q1=75 q2=90) contribute to the 2k fuzz pot completely cutting out the signal in the lower half of rotation? It sound pretty good maxed but it's a bad look to have a control that half works... 

Notes:

The diode/100k pair from the Antiquity Fuzz could be omitted or actuated via switch.
The q1 emitter resistor can be omitted via jumper.
The smoothing caps from C to B on both Q1 and Q2 are optional
All common fuzz face mods should apply and there are extra holes in PCB to help execute said mods