Proposition distortion questions

[stebur64]

I am wondering what is the purpose of the charge pump, IC TC1044 on my new Proposition Distortion pedal. Can we use the pedal at voltages higher than 9V ? Thanks fellow builders !

 

[Robert]

The charge pump doubles the 9V input voltage to around 18V.

You'd have to bypass the charge pump circuit if you wanted to power it from an external supply higher than 9V.

 

[Giorfida]

Scholz was always known to use a true bipolar supply (think it was +/-6v in the Rockman), so is it safe to assume the real Ultimatum used 2 9v batteries to supply a +/-9v?

 

[Robert]

Scholz was always known to use a true bipolar supply (think it was +/-6v in the Rockman), so is it safe to assume the real Ultimatum used 2 9v batteries to supply a +/-9v?

Nope, not this time. The two 9V batteries were in series and supplied 18V.

 

[Giorfida]

Thank you.
I look at how ambitious someone like Scholz was, and then there is me, who is too lazy to look at the schematics and see that it was a series/18v supply!

Guess it would be easier for folks to find a +18v supply back then vs a +/-9 supply!

 

[Robert]

The DC jack was actually labeled 12VDC, which I guess was more common back then.

I believe it was center positive as well, unlike most pedals.

 

[alienas]

Hello, i have also questions about this pedal.
For the moment i don't have RB1 and RB2 (i put sockets in case of) is it normal to have a dull sound ?
How to jumper the Jfet?
About selecting a J201, what do "on" and "off" mean in the build document? What must be on or off to measure Vgs and Rds?

and how does this circuit work? What the goal of the Jfet?

THX