will this work? (diodes and rotary switching)

[saxtim]

I was playing around with using a 1 pole, 12 position rotary switch to select different diode combinations on either the dist + or DOD overdrive 250 circuit.  

This is what I'm thinking: (copy and paste URL in new window)

http://www.geocities.com/mejafu/rotaryswitch.jpg


The plan is that in position one on the switch it can be a standard diode pair, then positions 2 and 3 add diodes for asymetrical clipping.  Position 4 cuts out D1-4 and moves to a new set of diodes (d5-d8), of a different type, so I could say have d1-d4 being silicon, then d5-d8 being germanium, and then if I copied again I could have LEDs or any other combination.  I figure this would allow a lot of experimentation and make the rotary switch like a virtual tone bank.

My question is though - take for example D3 and D4, when the switch is in position 1, I assume that D3 and D4 wont affect the signal? For D3 to have any effect the switch has to be in position 2, and for D4 position 3?  Is that right (that's the assumption I've based this working on.)

[Peter Snowberg]

My question is though - take for example D3 and D4, when the switch is in position 1, I assume that D3 and D4 wont affect the signal? For D3 to have any effect the switch has to be in position 2, and for D4 position 3?  Is that right (that's the assumption I've based this working on.)

Very good idea.

As you have it drawn, D3 and D4 will be out of the loop when the switch is in position 1, but positions 2 and 3 will only connect a single clipping diode. If you want to use the switch to select between combinations with more diodes in one leg or the other, you could just add diodes from ground to points 2 and 3 (anode to ground).

Happy hacking!
-Peter

[bobbletrox]

What a coincidence!  I was just trying to get my head around the exact same thing...but with mosfets thrown in for good measure.  www.tymguitars.com.au (located here in brisbane) sell a modified distortion+ based on this idea too.

[Ansil]

you should see my asy/sym

[bobbletrox]

I'll be damned if I can figure out how to wire up rotary switches  :oops:

[toneman]

u need to mount the rotary sw on the pcb next to the diodes and opamps.

or, use small pcb relays to sw diodes in/out.
that way all U have is (relay)voltage running to the sws on the front panel.

can't pickup any noise that way.

a PIC selector like the proposed by Keene might B usefull here(?)
especially for some kind of "chopper diode" scheme.
Chopping is doing filters.  Why not distortion(?)

tone

[Mark Hammer]

Take a look at the Warp controls labnote at Jack Orman's site (www.muzique.com).  You may find that the variation you want can be more easily achieved (and wired up) with a simple DPDT toggle and a single pot.