Growler Reissue Preamp Harness

The Gibson Tobias Growler has a single, quad-coil pickup (MM52CBJD3 or MM42CBJD3) which is split into 2 virtual split-coil inline hum-cancelling pickups.

Each virtual pickup is connected to its own 2-band EQ preamp channel with contour control allowing bass and treble cut and boost as well as mid boost or extra treble boost at the flip of a toggle switch. The amount of mid boost and treble boost are set by trimmers in the control cavity. The neck and bridge halves of the pickup can be blended to produce an astonishing range of voices from a single pickup. The Gibson Tobias Growler is truly a stealth-tone bass.

The DNTBT-18 preamp is powered from 2 9V batteries to create +9V and -9V. This arrangement allows the preamp to reproduce the lowest bass notes clearly with no attenuation or phase shifting. The power to the preamp is controlled by an internal switch which senses the ring contact of the jack to turn on the preamp when the cable plug is inserted.

We have a Wiring Diagram posted on the Bartolini.net website with full connection details.

This harness is complicated and challenging to install. We highly recommend having it installed by a professional and experienced luthier or technician. You can contact us at Bartolini Support to help you find an installer.

The cavity photo shows a professional installation done by Doug Somervell at Somervell Guitars who also provides tech support for Bartolini.