The AMT BC-1 Bass Crunch Bass Preamp is built on custom technology by АМТ using JFET emulation of vacuum tube clipping. Its wide adjustment range, in combination with the convenience of a stomp box, makes this preamp extremely versatile. 

»Bass crunch… BC-1 preamp is based on a two-channel circuit. 

CLEAN channel shapes the classic bass guitar sound characteristic for »old… amplifiers and allows both velvet transparent sound and slight compressed overdrive depending on the position of Gain control. 

DRIVE channel contains a number of over amplification stages and is intended for obtaining a modern sound from clean to totally overdriven. The High Mode provides additional possibilities in terms of range enrichment, heading towards higher sound density and aggressiveness. The adjustable 3-position mid-range filter combined with deep adjustments along the frequency ranges offer bassists rich possibilities in shaping the overdriven tone range. 

Controls: 

Clean 
Level – output signal level adjustment 
High – high frequencies adjustment 
Mid – middle frequencies adjustment 
Low – low frequencies adjustment 
Gain – channel sensitivity adjustment 

Drive 
Level – output signal level adjustment 
High – high frequencies adjustment 
Mid – middle frequencies adjustment by means of rejecter filter Freq. notch 
Freq. notch – cutout frequencies switch (rejecter filter) 500Hz, 330Hz, 230Hz. 
Low – low frequencies adjustment 
Pre. Notch – rejecter filter switch before Drive stage. 700Hz, 400Hz. 
Gain – channel sensitivity adjustment 

Overall Controls 
Blend – signal level balance adjustment between channels Clean and Drive 
Master volume – BC-1’s overall output level adjustment. 

Footswitch DRIVE – Drive channel on/off 
Led – Drive channel on indicator 
Footswitch HI/LO – Drive channel increased sensitivity on/off. 
Led – HI/LO mode with Drive channel increased sensitivity on indicator.