Garnet single-knob tone control

[mdcmdcmdc]

Hi folks,

I know there are a lot of threads on the forum about single-knob tone circuits, but I couldn't seem to find one dealing with adapting this particular garnet amp circuit fragment for use in a stompbox:



The closest thing I could find was the tone section of forum member rring's as-seen-on-tv boost.

I'd love to see an example of this in use in a stompbox circuit, if anyone happens to have one handy. Thanks!

[Renegadrian]

Why don't you wire it up one yourself, easy! just use ROG tube to fet topology and try!

[mdcmdcmdc]

I'm certainly planning on it—I'm just very new to working with these kinds of fragments and I'm always far more comfortable starting with a known circuit or at least a jumping off point. That way I know the problem is definitely ME if things don't fire up immediately.

[Mark Hammer]

I like "reciprocal" tone controls (i.e., more of THIS = less of THAT).  Of course, so do lots of other people.  The Defense presents exhibit A: the Big Muff Pi tone control.

The key aspect is the manner in which the complementary/reciprocal changes are introduced.  That can depend on pot taper.  In the case of the Garnet circuit, the treble boost produced as the resistance to ground for C2 gets smaller won't really occur until well past the midpoint of the pot's rotation.  And the treble cut produced as C3's resistance to ground gets smaller may also require much less than half the pot's value.  At first glance, and without ever using it, my gut response is that the circuit wants a W-taper pot (log in one direction, anti-log in the other, from the midpoint).  Sometimes you get lucky, and sometimes it only takes a parallel resistor along one leg to get the taper you want.