Colorsound overdriver 9V vs. power boost 18V

[Silvio55]

I want to build a clone of one of these pedals, wich are basically the same. I wanted to know what could be the difference in these circuits, I guess the 18V has more heardroom, thus less distortion and less "fuzzy" tone when run at higher gain settings, but if someone with experience with both circuits can give me a better idea of the difference it would be great!
Thanks!

[stonerbox]

Add schematics next time for higher chance of response.

I would say that you would get less dynamic and more "traditionally" compressed sound out of the 9v version and more headroom (since there are no diode clipping going on), less distortion and a tiny bit more high end clarity / treble out of the power booster. Some will probably say that I am totally wrong on the last part but that is just my personal opinion.

[Silvio55]

Thanks Stonerbox! I was decided to make the 9V version, but now I think I'll go for the 18V. I was intending to use as a boost in front of a Marshall jmp 50 watt that I always use with the volume/gain on 10 (it has a master volume, so don´t worry for my ears!), maybe the 18V power boost will work better for this.