12 volts on opamp/diode based distortion circuits

[Steben]

I'm guessing not, but is there any harm in feeding 9V pedals with 12V - given that the opamp circuit is in terms of bias symmetric?
Effects are:

-higher clipping tresholds of the opamps.
-possibility to raise the diode tresholds, giving bigger boost output and the use of big voltage treshold MOSfets

[Galego]

I guess it depends on the opamps you're using. I've used 4558's with bipolar + - 12v biased to gnd.

[tubelectron]

I'm guessing not, but is there any harm in feeding 9V pedals with 12V

Your'e guessing right. There is very few exceptions...

A+!

[R.G.]

Some pedals use 10V rated electro caps.   

[Steben]

Boss pedals ... OD, DS, ...
Ibanez .... TS-x

In the old official DS-1 schematic (the grainy one with settings pictures) I notice Supply filter cap rated at 16V and 6.3V for half supply voltage. Is it correct to ignore the other ones since they don't have voltage rating?
12V would do fine no?....

[tubelectron]

Some pedals use 10V rated electro caps.   

Ah, yes : R.G. is right, I saw it one time on a recent unit which used SMC - I was only thinking about the IC itself.