Would that be for a positive jack connection or a negative like on the boss pedals?
I don't understand. There was no power jack on the original Crybabies. 9V internal battery only. Hence my mod. Batteries did not last long if you were not diligent about unplugging guitar during breaks.
So a diode would be needed as well?
The diode prevents damage to the circuit in case an idiot tries to connect the battery (or power supply backwards). You'll see it on later models.
What voltage should the caps be?
A little more than the highest voltage in the circuit. 16V was popular when I did this.
What does the 220uf cap that is there now do?
There is no 220uF cap on my '70s Thomas Crybaby.
On my old Jen wha all they did was I think , a pos jack with no filtering.
"Jen wha" That's really Jen wah isn't it?