The preamp comes in two versions:

– Volume / Volume type allows control of each pickup individually.
– Volume / Blend version allows the pickups balance to be set with the Blend, and a Master Volume for the overall output.

Summary of Features & Basic Spec
– Classic Volume / Volume / Tone passive path version, replicating original J style wiring.
– Volume / Blend / Tone version for those who prefer a master volume.
– Push-Pull active/passive on Passive Tone.
– Class A FET input stage for great sound quality, with master gain trim preset adjuster.
– Highly responsive Bass and Treble control adjustments in active.
– Frequency Wheels to set the width of the bass and treble spectrums individually.
– Passive Tone is always operational, in both active and passive.
– Passive Tone has plug-in tone cap to allow easy swapping of the cap value for different roll-off frequencies.
– Bass control can be set as boost/cut or boost only, with an internal jumper link setting.
– Screw terminals for all external connections – pickups and grounding, for easy installation.
– Designed as drop-in replacement for standard J electronics with no physical changes to the instrument*.
– Design allows 9V Battery to mount beneath the preamp in a standard J style bass.

Basic Response, Gain & EQ Spec
– PASSIVE MODE: Neutral at response in accordance with passive control settings.
– ACTIVE MODE: Neutral at response when Bass & Treble controls are set to their centre clicks.
– GAIN TRIM: Internal Trimmer 0-12dBs setting overall gain of active circuit.
– BASS CONTROL: +/- 18dBs Cut/Boost with internally adjustable shelf frequency 40–200Hz.
– TREBLE CONTROL: +/- 18dBs Cut/Boost with internally adjustable shelf frequency 1kHz – 7.5kHz.