Looking for a little help with Joe Davisson Shocktave.

[cab42]

Quackzed,

Thanks for tips. I was thinking about something like the pot instead of the 10K. I may end up actually knowing what I'm doing.

To use the pot as a variable resistor I need to connect one of the outer pins to the middle pin? I guess I can measure the resistance on the pot and replace with a fixed resistor.

One more question: It seems that it works for some people using the stock 10K resistor. Is it variations in the transistors that causes the need for biasing? Could I fix it by trying different 5089's? I have around 20.

Regards

Carsten

[Quackzed]

Yes,  (i think) its the hfe or gain that determins how you need to bias the transistor, from what i've learned here..so if you had a lower gain transistor in there (like me) you would most likely need to adjust the bias( bias determines gain...i think its collector resistor/emitter resistor that determines the gain of the transistorso naturally making the collector resistor a higher value will increase gain... 5089's are high gain low noise transistors that (usually) are pretty consistent gain from @600-900 or so??? so yeah... but just remember thathigh frequency content(treble) can create tracking issues... (i have a really bright strat type guitar with no tone controll that doesn't work as well with this box as my humbucker equipped guitar...)
if i were to adjust this pedal for THAT guitar i might add a cap to ground at the input(low pass filter) to roll off some highs and then increase the collector resistor of q2 to compensate for the gain loss off cutting highs...
i like how the attack seems sort of rubbery and analog(?) it's got a nice animated tone..not lifeless like a synth... caught myself trying to learn the solo from "fool in the rain" tho pagey used a mxr(blue box?)pedal on that; it's a similar tone and i can definately cop that cool tone with the shocktave!

[cab42]

I got it working yesterday. It sounds as I had hoped for, not very different from RDV's sound sample.

It doesn't sound very good when the gain pot is maxed out, but if i turn it down a little and find the right mix setting it's great

Quackzed, Thanks for all your tips.

Regards

Carsten