different voltages and "more headroom"

[Adamixoye]

Hi, this may be a bit of a dumb question, but I hear about using differing voltages for "more headroom," but I'm not sure what that means practically. Since this is specifically in the context of overdrive/distortion pedals, I'll ask simply---for two identical pedals at the same drive/gain settings, one at 9V and one at 12V or 18V (if this is allowed by the pedal), which pedal has more drive/gain?

[ryansalmond]

Results may vary by pedal, but in my limited experience the lower voltage one will distort more easily and more often, like a lower wattage amp. Like a higher watt amp, the one with more volts will stay somewhat cleaner, and have more dynamics, arguably sounding "bigger."

[Bakkster_Man]

I'm guessing this is referring to higher voltages meaning the clipping can happen further from the noise floor, meaning less noise at higher gains.

[bongomania]

Originally Posted by Adamixoye

for two identical pedals at the same drive/gain settings, one at 9V and one at 12V or 18V (if this is allowed by the pedal), which pedal has more drive/gain?

Originally Posted by ryansalmond

Results may vary by pedal, but ...the lower voltage one will distort more easily and more often, like a lower wattage amp. Like a higher watt amp, the one with more volts will stay somewhat cleaner...

+1

It will be different from one pedal to the next, but generally lower voltage means earlier (more) distortion.