Mark Hammer Tube Sound Fuzz

[iCommunism]

Hi folks

I've been pretty smitten with making a TubeSoundFuzz or red llama like box, but what i want to do is basically what Hammer has done.
This will be the first guitar effect I will make that has significant mods, and I will likely adapt the tonepad board and etch my own. Since i am new to all this, before all i am doing is component-by-numbers kits, I need some help =)

here is a schem in case you are not familiar with the red llama or TSF
http://www.geofex.com/FX_images/mhtsf.gif

Anyhow... I plan to follow Hammer's advice pretty close regarding the inverter area of the pedal, but I would like to use a  BS170 mosfet (instead of a dual opamp) in front of the inverter stages, and ignore the filter section after the inverters. also I think i will use about 50pf ceramics in the feedback loops, but i should probably breadboard it and try various values? Is that so low?

I have a few questions: How do I place the mosfet to drive the inverters properly? I really have no idea. Should I look at simple boost circuits using the bs170 and use that verbatim?  do I need to place the booster before or after the 100k + 0.1uf cap (right in front of the 2 inverters)?

One more: would the fuzz pot in the first feedback loop or the TSF circuit have a place in my circuit, or should I omit it totally?

Also for anyone who has built the Hex Inverter pedals like this, Does the filter after the inverters help that much? I think I do not care, but do you think that is very necessary?

Thanks.

[Mark Hammer]

It sounds to me like you're really trying to build Frank Clarke's Hot Harmonics ( http://gaussmarkov.net/wordpress/circuits/hot-harmonics/ ) and don't realize it yet.

4049s do a nice job at providing a very vocal-sounding grunt (think Keith Richard or Mike Campbell), but to help them along, you gotta roll off those highs.  That's the reason for the feedback caps being as high as they are.  I suspect a 50pf value will be too low to provide pleasing tone, but your tastes may differ.

The tone control does not have to be as complex as that shown.  I've made a couple with an SWTC treble rolloff and it works just fine.  Not the sort of tone circuit that provides a huge change in character, but it helps to retain the character of the circuit and allow you to compensate the pedal's sound such that you don't get too bright or too dull a sound for the amp settings.

Stick a 1-10uf cap after the output of the last inverter section, then wire up a 1k resistor, then a 10k pot with one outside lug to the 1k resistor and the other outside lug to the volume pot.  Now stick a .022uf cap between the wiper and ground.  Done.

[iCommunism]

Thanks a bunch, checking into hot harmonics, I found a few other schematics that look close too.

it looks like I will have to prototyping to do. I think i will make a flat out Way Huge Red Llama clone on top of the hot harmonic-alike.

anyone have any other tips for these circuits? Any other tips for coaxing really huge tube sounds or other fun corners out of these things?
Also was the hot harmonic-like transistor/opamp driven hex inverter ever built into a commercial pedal?