The Bartolini AGB/918-2 is an Adjustable Gain Buffer/Pre-Amp. It features an adjustable low-noise gain from 0 to 12dB with a superior flat frequency output response and low noise floor. This preamp can be used with either one 9 volt battery (9 volt operation), or two 9 volt batteries (18 volt operation) which yields 6 dB extra headroom.
The buffer isolates the pickup output so that outboard effects, even the ones with "True Bypass", and amps do not weaken the pickup's output. It operates as a buffer for any of the Bartolini onboard Pre-Amps, such as the NTMB and TCT 3-Band EQ’s, NTBT 2-Band EQ, or stand-alone in front of a passive tone control. It operates at either 9V or 18V.