Some people have complained that the CB30 lacks a little gain, I'm not sure it does but here are a few mods and suggestions which will allow you to pump up the available gain without removing too much of that Vox character; Reduce the value of R1 (maybe 10k), Increase the value of C4 (47n or higher), Increase the value of C7 (1n-10n), Remove R7 or just reduce it's value, Make Q5 a jfet gain stage instead of just a buffering stage. NOTE - these modifications will alter the frequency response of the pedal somewhat, it's about tweaking it to your taste while attempting to retain that Vox character!