The L5 Preamp Drive Channel is an adaptation of the second channel of the Lab Series® L5 amplifier, originally released in 1976 and discontinued in 1981.
The Lab Series L5 amp was designed to compete with the Fender Twin Reverb, and the first channel was specifically designed to be Fender-inspired. However, the second channel was completely original from the ground up, with active tone controls, a parametric midrange, and a unique (and patented) multi-pole fixed EQ called the “Multifilter”.
The drive channel of the L5 was most famously used by Ty Tabor on the first four Kings X albums. (BB King also used these amps, but only the clean channel, for which we have a different project.)
This project recreates the entire signal path of the drive channel except for the multifilter—including the OTA overdrive, compressor and master volume. It also runs on the same +/-15V voltage as the original unit. The only change we’ve made is to convert the input stage from inverting to non-inverting. This reduces the noise, but the way we’ve designed it, the input impedance and frequency response are exactly the same as the original amp’s “Lo” input (the higher-gain mode designed for guitar).