Electric Mistress deluxe, boost post effect

[reeko81]

I've read many posts about using a simple transistor booster after effects output, but before testing it i need to solve my little trouble.
My DIY Electric Mistress seems to have that volume loss only when regen control is very low, otherwise when using high regen settings it seems to boost the overall signal..
I think this should be normal, but my real trouble is the next one:
can I power this simple boost with the +15V i get after my 7815 on the Electric Mistress pcb?
What simple boost you think should work properly for this purpose^
I've read so much about that LBP1 ( or LBP2 don't remember exactly....), but is there a better boost for this purpose?
P.s.
I forgot to mention that I've built that generalguitargadget Electric Mistress clone.
It works flawessly!