A Pair o' Preamps - Echoplex and Tillman

Just a couple of little preamps that have been requested.  Some people swear by these little circuits and use them at the input of other effects because they like the way they colour the sound, so a quick build for people to experiment with.

A couple o' variations:

EchoPlex Preamp with charge pump for 18V from a 9V supply

Early version EP3 with volume control

Tillman with Gain Switch