electra distortion- how to add extra pot for clipping adjust

[addnoize]

i made an electra distortion a while back. it was my first ever pedal project, and i must say it has turned out to be my favourite.

it's a simple single transisitor crunch with a volume pot. diagram is here - http://www.j.philpott.com/effectronics/ (follow the beginner's links, schematic link is about a 1/3 down from the top of the beginner page)

looks a bit soviet union with no paint and a crap stomp switch, but that's how i'd like to keep it, perhaps i can put some bold capitalized graphics on it with backwards 'r's.  :lol:  

http://www.users.bigpond.net.au/googgyegg/powercuts/graphics/electra.jpg

now i'd like to do a simple mod - how can i add an extra pot to adjust the amount of clipping/gain so that i can have some direct control over the level of distortion? now when i want less distortion i have to turn my guitar down and the electra pedal volume back up.

thanks - addnoize

[Tim Escobedo]

Two easy way and different ways to do this. One way is to wire a volume pot on the input. Anything over 100k should be OK. Another way is to replace the emitter resistor with a variable resistor 10k pot. There are subtle tonal differences either way. Both worth a try.

[petemoore]

http://www.muzique.com/lab/main.htm
 Check out the warp controls article in the labs notebook!

[addnoize]

Tim Escobedo - i wired up the two options and i'd say the 10k variable resisitor wins hands down. it tends to get a little too fuzzy at the top end so i swapped out one of the silicon diodes for one germanium....works nicely! at the moment i'm just using pins 2 and 3 on 10k a log pot (i really need a linear).

petemoore - that article is great i've printed it out already. i have read through once but will need to dig a little deeper to understand everything. thanks.

-addnoize