Individual switching of 3 gain stages of the Insanity Box

[syzygy]

I would like to add three DPDT switches to individually switch in and out the different gain sections of the insanity box.  And I'm considering adding potentiometers to replace the trimmers for more versatility.

I'm not sure the right locations to add the switches because I don't want to unnecessarily bypass any needed components.. but here's my guess;

First let me define some locations:
(a) the location immediately before the input to the RC4558 IC
(b) the location immediately before the input to the CMOS chip
(c) the location immediately after the 100k trimmer fronting the minibooster stage
(d) the location immediately after the .1 uF cap after the minibooster stage FETs.

Attach the first DPDT to bypass the drive stage between (a) and (b).
Attach the second DPDT to bypass the CMOS section between (b) and (c).
Attach the third DPDT to bypass the minibooster stage between (c) and (d)

Will this work?  The three different stages should sound great on their own, right?  Or should there be some additional resistors or caps to make them sound right when others are switched out?

Comments welcome!

[smccusker]

You would probably have to add some pulldown resistors to stop horrible popping when you hit the switches.

[syzygy]

How do I know which value resistors to use, and where does a pulldown resistor usually show up in a circuit?

Thanks!

[kusi]

hi

have you build the insanity box?

i build one on my prototypingboard, and this pedal needs some modifications! (imho :wink: )

- change the input-cap to 22n or 47n
- change the 470nF cap in the op-amp stage to 68nF.
- change the gain-pot to 250k log. with 20k pre-resistor
- change the clipping-diodes to red leds (not very important)
- change the 110nF cap in the mini-booster stage to 220n or 470nF
- source-resistor in the mini-booster is needed!
- add a marshall/fender tonestack, not a BMP!


has anybody here experiences with insanity-box mods?

greetings from switzerland
khe

[syzygy]

have you build the insanity box?

I haven't built it yet, but I am about to buy parts soon.  I'm interested in your prototyping experience for this pedal -- how do your mods change the sound of the pedal?  And how did you go about finding which values to use?

source-resistor in the mini-booster is needed!

And at what location in the schematic is that, and what value do you recommend, and why?

It would be good for more people to comment on their build experience of this pedal since it looks like it has some great potential.

Kusi, do you plan to build the pedal with perf board, or are you going to use the existing PCB and squeeze changes into that?

Regards