I've decided to build Joe Gagan's Dino Drive after choosing between that, the Dino Fuzz and the Bronto Boost.  The Dino Drive has an optional 1uF capacitor on the input for 'Plexi Voicing' that I'd like to add to the circuit via a push/pull pot (to save the room that would otherwise be required for a toggle).

Which side of the capacitor would be the best to put the switch to avoid popping...or to produce the smallest amount of 'pop'.  Should the switch be on the drive pot side of the capacitor, or the side that goes to the base of Q1?  Here's the schematic:



TIA!
Phillip

Put a 1meg resistor in series with the 1uF. Use the switch to short the 1meg resistor.


Bye,

Joep

BTW do you made a PCB for it? Can you share it? I think Joe Gagans pedals are among  the most underrated pedals on the forum. The soundsample on Ampage are great!

Working on a PCB now

Phillip

cool!

Another way to do it is to exploit the properties of series capacitors.  Remember that they behave like parallel resistors, in that the parallel value will always be lower than the smallest-value cap in the combination.  By selecting combinations, and NEVER lifting one end of any of them, all caps are always draining and pop-free.

You can use this pleasant property with a 3-position (on-off-on) SPDT toggle switch.  So, using the formula 1/C = 1/Ca+1/Cb+....1/Cn, select a combination of 3 caps.  When all 3 are in series,  that will give you the lowest value series capacitance.  Now figure out which one of the caps you can shunt for an intermediate value, and shunt two caps for the maximum value (only one cap effectively "in series" so full capacitance).

Simple example:  A 1uf and .47uf cap in series yield a combined capacitance of just under .32uf.  Shunt the .47uf cap and the effective capacitance is 1uf.  Shunt the 1uf cap and the effective capacitance is .47uf.  Voila.  Three different cap values from 2 caps....and silent switching.  

If you want to get really fancy, use a DPDT 3-position toggle to get cap switching and LED status indication.