Highway89 needs a TONE stack

[cbriere]

This circuit has captivated me for it's
amazing capabilities by means of guitar volume control.
It can range from slight OD to full distorsion without too much
volume variation...cool...

So,
I have started to mod. this circuit to my taste but i need some advise.
What i want is a 2 control tone stack (bass & treble) .

I have tried to use the existing tone stack by moving it towards
the output of the circuit but it has too much volume variation with treble pot rotation.

Bass control should boost or cut the low end.
Treble control should act same as in the TS-808 circuit.
   as it should shift the high frequency rolloff down to 1-2K
and i want to to this passively of course.(no opamps)


any advise?

[Doug_H]

Just try a typical marshall/fender TMB tone stack on the output. If you only want 2 controls, sub the mid pot with a fixed resistor.

Doug

[343 Salty Beans]

another suitable idea is to put the big muff tone control on that sucker, there's a vero layout in Dragonfly's layout gallery.

But since you're wanting bass and treble controls, i can't help ya out much...

[MartyMart]

I stuck a BM tone stack between " C4  and R8" as I wanted it to be a "three knob" device.
Works remarkably well and has a great range of tones.
Can't remember if it was a "stock" BM or slightly adjusted ... !
C3 became 470n as I didn't have a 680n at that time, I dont think that changes the tone
or gain at all ?

MM.

[Doug_H]

I don't find the gain control particularly effective and I would like to re-do that. In fact I may just eliminate it: replace RGAIN with a fixed 10k resistor and omit C3, connecting C4 to the collector.

Doug

[cbriere]

I don't find the gain control particularly effective and I would like to re-do that. In fact I may just eliminate it: replace RGAIN with a fixed 10k resistor and omit C3, connecting C4 to the collector.

Doug

what do you mean by "not effective" ?
On my prototype, Gain control has a wide range of variation on the sustain and gain of the circuit.
At max i get lotsss of gain, endless sustain. In fact it sound a lot like on the sound clip of yours....
Only bad thing about that pot is the fact that it has DC on it , so it's scratchy when in rotation.
I'm thinking of reconnecting the pot to ground.
So circuit would have a fixe 10K , same as you proposed , but add a gain to ground pot between
collector and C4 (C3 is removed).

(Tone stack issue): It has moved to coll. of Q3.
tried a Fender stack, nope sound too much trebly.

So i put a new circuit.

-----0.22U--+-----0.01U-----+----------------+
                 |                      |                    |treble
                 |                      |              POT 100K--------
                 15K                0.1U                 |
                 | bass              |                    |
               POT 100K --------+                    |
                 |                                           3n3
                 10k                                        |
                 |                                            |
                 gnd                                        gnd
                   
looks like this.
Bass is like original, treble is rewired .

issues remaining:
Cap 3n3 is still not final.
Bass has not enough gain.?
circuit is still too trebly...?

[cbriere]

ok, i finaly comploeted this one this weekend,
in a box , it has 4 knobs, gain/bass/treble/volume,
tone stack has been chaged for a fender type (mid is a fix resistor)
and moved to the output.
I will try it with the band tonight, well see. 
i hope to be able to use it,
for rythm parts -volume at around 5 and sound to be overdrive
and for solos --guitar volume maxed.