A different kind of SB-2 tone mod (on/off switch)

[bhen]

I have 2 SB-2s, one unmodified and another one with the Vol/Vol/Tone mod from Bayou. This uses a .047uf cap, and I noticed that I basically only use two settings of the tone control: 100% ("off") and 20%.

I saw that you can buy .033uf caps, which appears to be right where I usually set my tone control. This makes me wonder if it's possible to integrate this into the circuit of the unmodified SB-2, so I could control the cap with a micro-switch. In the off position it would not influence the tone, and in the on position it would be full on, i.e. right about where I usually set the tone control too.

Has anyone ever done anything like this and could provide me with a diagram? If not, where and how would I have to integrate the switch, and how would I have to solder the cap to the switch?

[Ken Baker]

Possible, but probably not a matter of simply switching a .033mfd cap in and out of circuit. In a simple treble-cut tone circuit, the amount of frequency filtering depends on the values of the cap and the pot in combination. One affects the other and is, in this case, called an R-C circuit (Resistance-Capacitance circuit).

You'd need to substitute a fixed value resistor for the tone pot in this circuit...


http://www.bassesbyleo.com/images/g&..._with_tone.jpg

...the value of which would be the same as the pot's resistance at the setting you like. You'd build a circuit consisting of a SPST switch, the resistor (1/4 watt is fine), and the normal .047mfd cap. Connect one lead of the cap to ground and its other lead to one lead of the resistor. Connect the other lead of the resistor to one pole of the switch and the other pole of the switch to the signal hot lead after both volume pots.

I think that should get you where you want to be. Should. At least conceptually. YMMV.

Ken...