Switchable Capacitors

[letsgocoyote]

I'm a beginner fx builder, me and my friend have built a coupleafew pedals so far, with some failures and some good successes.  I'm jsut beginning to grasp the different mods I can make to different schematics for different sounds.  Anyhow, I want to build and overdrive for myself which is going to have gain, volume, and a 'tone switch'.  I want to use a SPDT to make it be able to switch between two different capacitors for the input capacitor, to give me a fatter and a brighter setting.  Should the SPDT go AFTER gthe caps as in figure A or before as in figure B?  Thanks.

P.S.  A gain knob can jsut be a pot right at the input of the schematic, right?

[petemoore]

  Either one will work and the signal path depends on the mechanics of the switch to be completed.
  I prefer paralleling two chosen values and lifting one of them [via switch] or seriesing chosen values and shorting across one, this way there is always a hardwired signal path.
  paralleling increases UF value
  seriesing decreases UF
  It's a bit trickier to choose the values, I like series, starting with the non-switched cap as thick', then trying the other cap values [when the switch isn't shorting across the 2nd cap] to find the series combination which ='s a value chosen for the 'thin' sound.
  A gain pot at the input can have the same wiring assignments as a guitar Vcontrol, sometimes it's nice to have a couple gain controls like this at the input, the one in the box sets max input gain, the guitar volume takes it down from there, in this way adjusting max gain [slamming guitar volume to 10] like the guitar was set for 8 or 9.
  ^ described is function and wiring of a pregain wiring assignment like a volume control, one lug to ground.
  another way is with a series resistance which is variable [no ground connection on pot, just the other two lugs].
 

[letsgocoyote]

thanks