Impossible? AMZ mini booster switching challenge!

[DuoJet]

Admittedly this might be impossible but it's worth a go. I'd like to install my newly made Mini Booster into my Gretsch Duo Jet. I'd really like to avoid installing any new switches so my question is this: I only use one position of the tone switch which is a 3 position toggle on-Off-on which is basically this (please excuse the massive image)



I'd ideally like to use one of the positions on the switch to connect C6 to the output of the Mini Booster to boost the gain of the circuit and retain its' functionality as a tone switch. So what do you think? Can it be done?

[Quackzed]

well, if you ONLY use the middle position of the switch, the off position, then functionally you wouldn't need the switch for that purpose and you could cut it out... leaving the center lug unconnected as in the middle position, then use the switch( the center lug to ground , and one of the outside lugs to point A of c6) so that the  switch is now a c6, on-off-off, switch. if there were another point on the schematic where you wanted to try a cap to ground /resistor to gr. etc... you could attach it to the other unused outside lug, and have 2 switched variations... 1 with c6 to ground -2center off(normal)- and 3 one other 'something to ground sound'... with that switch.

[DuoJet]

I see what you're saying but I should have said that I use two positions, the off and one of the on settings. My bad. Would it still be possible to use the spare on position to switch c6 on the circuit or am I out of luck? I'd still really like to keep some vestige of a passive tone control on this thing.

[earthtonesaudio]

The two switches represent the two sides of the SPDT.  Shown in center-off position.

The resistors are to prevent popping.

[DuoJet]

Just wired this up and it works a charm! Id never thought of sending the common to ground. Thanks so much!

[earthtonesaudio]

Excellent!

[DuoJet]

I'm noticing that connecting c6 gives a heck of a kick to the treble output of the circuit. Is there a way to change the value to something else to lower the treble response?

[earthtonesaudio]

To tame the treble response in your setup I would add a resistor in series with C6.  Maybe about 100 ohms.  This will cause the gain to increase with frequency up to a certain point, after which the gain will not increase any more.  Often called a "shelving" filter.

[DuoJet]

Very interesting! Would I place the resistor on the positive or negative end of the capacitor? Ideally I'd like to achieve leoven oates EDIT: (thank you auto correct) LESS GAIN and less treble than usual when switching c6 to ground so that it's a little more subtle. Would playing with the values of the shelving filter resistor allow me to accomplish this? Thanks for all your help so far, I love these little problem solving missions- they open up new possibilities for so many future projects!

[earthtonesaudio]

Yep, as you increase the value of the resistor in series with C6 it will reduce both overall gain as well as treble, making the effect more subtle.

Order doesn't matter for series passive components.

[R.G.]

Order doesn't matter for *any* components where you don't (a) look at the intermediate junctions (b) let current out of them or (c) allow energy to radiate away from the middle, which I guess is really a version of letting current leak out.