GLL2K

Thank you for your recent purchase of a Boscoe GLL2K preamp!  This is a replica of the latest bass preamp (v1.3) used in G&L L•1500, L•1505, L•2000, L•2500, ASAT, and Climax basses.  Each preamp has been individually tested before shipping and should be a drop-in replacement for the preamp on newer basses.

If you have an older bass with the v1.0 or v1.1 preamps, you will need to remove the 10K ohm resistor that's soldered inline with the wire connecting the preamp to the switch.  Newer G&L designs (including this one) have this resistor integrated into the preamp.

When assembling, make sure to complete all connections before attaching the battery.  The preamp should be smaller than your existing preamp, so you shouldn't have trouble getting it to fit.

Carefully strip and attach wires to the screw terminals.  Tinning the ends of stranded wire with solder is recommended to ensure a good connection.  Make sure the pins on the bottom of the preamp aren't in contact with conductive paint or metal - cover with electrical tape or other insulation as needed.  You will need a precision flathead screwdriver to tighten the screw terminals - 1.5mm to 2mm (1/16" to 5/64").  An eyeglass repair kit will come with these, otherwise they can be bought at hardware stores or Amazon for less than $10.

The connections match the layout used in all recent G&L preamps.  The back of the preamp has the connection points marked.  They are as follows, along with the wire colors usually found in newer G&L basses.  Please confirm the colors before connecting!

• 9V+ (left side, red)

• INPUT (left side, white)

• GND (left side, black)

• OUTPUT (right side, yellow)

• SWITCH (right side, red)

Should you encounter any noise in the circuit, make sure everything is grounded and that the wires are firmly in the screw terminals.  A multimeter can help confirm continuity here.

Good luck and please contact us if you have any questions!  Below are some pictures from a customer's recent installation that may help and some close-up pictures of the preamp.