TS808 - tone control mod

[yeeshkul]

Guys did anyone of you try to substitute the 25k lin pot with 50k lin pot with 33k resistor across the lugs? 50k||33k = 19.8k and it should behave like a reverse log... just thinking. The originals used to have 20k reverse.

[Mark Hammer]

The classic 3-knob TS uses a single pot to perform two reciprocal functions.  In one direction it increases the gain of the tone-stage at increasingly higher corner frequencies.  In the other direction it adds a second .22uf treble-cutting cap in parallel with the existing .22uf cap.  The two functions are set up reciprocally so that doing more of the one gets you less of the other.

So where is the law that says you can't disaggregate these two functions and adjust them independently?    Run one pot for treble cut from the junction of the 1k/10k/.22uf meeting point after the clipping stage to a .22uf (or anything else you like, it's your pedal after all), which goes to ground.  Run a 2nd pot from the inverting (-) pin of the tone stage to a .22uf cap and gain-limiting fixed resistor (which could be 220R but could also be larger if you're not a big fan of the upper midrange honk) that also goes to ground.  Those caps can be anything 10k or larger.  If larger, you can tinker with a parallel fixed resistor to set the range of control.

For that matter, if you want a more complex tonal control, use a 50k linear pot for the treble-cut, with the wiper going to the 1k/10k/.22uf junction, and each of the outside lugs going to a different value cap (e.g., .15uf and .33uf).  For the treble boosting, run the pot from the inverting pin to two RC networks to ground, as is done in the Rat.  You can pick your corner frequency and boost adjustment to taste.

Come to think of it, that'd actually be a sweet TS.   Three knobs is fine, I suppose, but 4 knobs that lets you nail it is better.

Funny how sometimes you get so used to seeing something a certain way that you can't imagine it any other way.

[yeeshkul]

Thank you Mark, i definitely have something to think about now  . *thumb up*

[yeeshkul]

... if you want a more complex tonal control, use a 50k linear pot for the treble-cut, with the wiper going to the 1k/10k/.22uf junction, and each of the outside lugs going to a different value cap (e.g., .15uf and .33uf). 

Mark shall the caps on the outer lugs go to the ground?

[Mugshot]

The classic 3-knob TS uses a single pot to perform two reciprocal functions.  In one direction it increases the gain of the tone-stage at increasingly higher corner frequencies.  In the other direction it adds a second .22uf treble-cutting cap in parallel with the existing .22uf cap.  The two functions are set up reciprocally so that doing more of the one gets you less of the other.

So where is the law that says you can't disaggregate these two functions and adjust them independently?    Run one pot for treble cut from the junction of the 1k/10k/.22uf meeting point after the clipping stage to a .22uf (or anything else you like, it's your pedal after all), which goes to ground.  Run a 2nd pot from the inverting (-) pin of the tone stage to a .22uf cap and gain-limiting fixed resistor (which could be 220R but could also be larger if you're not a big fan of the upper midrange honk) that also goes to ground.  Those caps can be anything 10k or larger.  If larger, you can tinker with a parallel fixed resistor to set the range of control.

For that matter, if you want a more complex tonal control, use a 50k linear pot for the treble-cut, with the wiper going to the 1k/10k/.22uf junction, and each of the outside lugs going to a different value cap (e.g., .15uf and .33uf).  For the treble boosting, run the pot from the inverting pin to two RC networks to ground, as is done in the Rat.  You can pick your corner frequency and boost adjustment to taste.

Come to think of it, that'd actually be a sweet TS.   Three knobs is fine, I suppose, but 4 knobs that lets you nail it is better.

Funny how sometimes you get so used to seeing something a certain way that you can't imagine it any other way.

on a standard pcb layout from tonepad, how do you actually do that? im asking the guys here to post an illustration on how to do this, im new on DIY stuff, so maybe ics will help?