Adding a tone control to a Tillman preamp for a piezo

[alex_spaceman]

Hi everyone, I've built a couple Tillman pre's for use with piezos and been happy with the result, but I've been asked by a friend to make one for his autoharp with an added tone and volume control.

Can I simply add a second stage for the tone (ie a big muff tone stack or a ts/eternity stage) followed by a standard output volume (board to lug 3, out to lug 2, lug 1 to gnd) right after the tillman or would that affect the benefits of the pre/buffer itself in terms of impedance/output etc?

Any input or suggestions for an alternative circuits are welcome. i'm leaning towards sticking with the Tillman as he has tried it already on the instrument (he already has one i previously made for him) and sounded fine though a little dark. The tone stack on the eternity (called glass, basically a ts tone control with a few value changes) works very well in brightening up the sound, so I thought of it as a good fit.

Thanks in advance!
Alex

[drolo]

Hi,

Here are some suggestions from Tillman himself:

Bypass R2 with a small value capacitor for a treble boost.

(on http://www.till.com/articles/GuitarPreamp/)

You could replace the R2 resistor by an equivalent pot and connect that cap on the wiper and to ground (like on a fuzzface). And a simple volume pot at the end.

I think the TS tonecontrol will eat too much of your signal and you would probably need a second gain recovery stage after it.

[alex_spaceman]

I think the TS tonecontrol will eat too much of your signal and you would probably need a second gain recovery stage after it.

That's what I feared as well. That said, I'd still be using half an op amp for it, so I could use the other half for that purpose (klon buffer?). Any ideas on whether that would work?

Had a look at the presence mod, could be a nice option to keep things simple should a tone stack+output buffer not be a viable option.

Thanks!