Treble-pot for Sonic Distortion?

[kashmir]

I built a Sonic Distortion according to GGG's schematic (http://www.generalguitargadgets.com/diagrams/sonic_sc.gif). It's a nice sounding pedal as is but I prefer a little darker tones so I would like to add a separate treble-pot on it. I have read Jack Orman's article (http://www.muzique.com/lab/atone.htm) so I have the basic idea how to do it; I have a question concerning "the isolation resistors" though. In Sonic Distortion there isn't too much gain to waste so I'm wondering what would be the ideal resistance value for this resistor? Would a 47 k resistor be a safe choice? How about the treble pot? I thought that I would replace the 6,8 k resistor (R12) with a 10 k potentiometer... Could a 1,8 k fixed resistor and a 5 k pot serie combination be a better choice?

[petemoore]

  Smaller cap limits the attenuation to higher frequencies.
  They don't tend to sound like they limit overall volume as much, but HF's can certainly help cut through a mix.
  I just picked out a capacitor value [by placing it in the testclip wires which were connected inside the bypass at the out put and goes to ground...anyway find a cap that barely does or slightly over-does the treble rolloff. Use that value and put a pot in series with it...adjust values as necessary.

[kashmir]

That's a nice idea but I'd rather like to add the treble pot to the tone stack. Thanks for the tip anyways!

[petemoore]

  Take a look at AMZ, Labs Notebook, or download Duncan Tonestack Calculator, an interactive 'tonefinder'...lets you see and 'try out' tonestacks of various ilks.

[kashmir]

Did you look at the link in my first post (AMZ Dual Tone Control by Jack Orman)?

I know how to add the treble-pot to Sonic Distortion's tone stack - I'm just a bit unsure about the ideal resistor values in Sonic Distortion -context... A quote from Orman's article: "To reduce interaction between the sections, a pair of 47k isolation resistors (R1, R2) have been added on the output to mix together the signals from the two sections."

[kashmir]

BUMP

I built the SD-9 on veroboard so I wouldn't mind to experiment (read: solder and desolder) much... If I don't get any other suggestions I'm going to use a 10 k pot and 47 k isolation resistors.