Boscoe Music GLL1K — G&L L•1000 Wiring Harness — Control Plate / Full-Sized Pot Version

THIS LISTING IS FOR: CONTROL PLATE / FULL-SIZE

• 15mm-long shafts
• 6.5mm threaded bushings
• 24mm full-size potentiometer bodies
• Intended for conductive metal control plates
• Recommended for CLF Research-style G&L installations with adequate room for full-size controls

For most genuine G&L control-plate installations with sufficient cavity space, this is my recommended version.

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Boscoe Music GLL1K — G&L L•1000 Wiring Harness

The Boscoe Music GLL1K is a complete, prewired replacement wiring harness for the classic G&L L•1000 passive electronics system.

It includes the Volume, Treble and Bass controls, output jack, three-position pickup-mode switch, passive tone components, wiring, knobs and installation hardware needed to replace the control harness in an L•1000-style bass.

Instead of reproducing the original complicated point-to-point wiring, the GLL1K moves the difficult parts of the circuit onto two small custom circuit boards:

• A central wiring PCB contains the passive tone-network components and provides clearly labeled screw-terminal connections.
• A second PCB mounts directly to the ON-ON-ON pickup-mode switch and implements the classic Parallel / Single Coil / OMG switching.

The result is the familiar L•1000 circuit in a much cleaner, easier-to-install and easier-to-service package.

No battery or active electronics are required — the GLL1K is completely passive.

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Designed for the G&L L•1000

The L•1000 may look simple with one pickup and three knobs, but its electronics are unusually sophisticated.

The GLL1K recreates the classic L•1000 control system with:

Volume — 250kΩ audio taper

Treble — 250kΩ audio taper passive treble cut

Bass — 1MΩ reverse-audio taper passive bass cut

3-position ON-ON-ON pickup-mode switch

The pickup-mode switch provides:

PARALLEL — both MFD pickup coils operating in parallel for the clearest and most open response.

SINGLE COIL — one pickup coil operating by itself for a leaner, more focused sound. As with any true single-coil mode, some additional hum compared with the two-coil modes is normal.

OMG — the famous L•1000 high-output mode. Both coils participate in a frequency-dependent series arrangement using the traditional OMG capacitor network, producing the enormous low end and output associated with this setting while retaining more definition than a conventional full-bandwidth series humbucker.

There is no active bass boost in OMG mode. The entire circuit remains passive.

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Modernized Construction

My goal with the GLL1K was to preserve the unusual L•1000 electronics while making them substantially easier to install and service.

The original circuit requires numerous point-to-point connections between the pots, capacitors, resistor and multi-pole toggle switch. The GLL1K puts that complexity on purpose-built PCBs while retaining the original circuit functions.

Features include:

• Complete prewired harness
• Custom central wiring PCB
• Custom pickup-mode switch PCB
• Screw terminals for easy connections
• Prewired mono output jack
• Prewired Volume, Treble and Bass controls
• Traditional Parallel / Single Coil / OMG switching
• Passive PTB-style Bass and Treble controls
• No battery required
• 6mm knurled potentiometer shafts
• Three matching push-on knobs
• Mini screwdriver
• Self-adhesive neoprene pad for PCB insulation
• Individually assembled and tested by Boscoe Music

A typical installation requires connecting the pickup, bridge/common ground and the prewired sections of the harness at the labeled screw terminals. The harness is specifically designed to minimize the amount of soldering and point-to-point wiring required.

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Pickup Compatibility

The GLL1K is designed around the four-conductor G&L Magnetic Field Design (MFD) humbucker used with the L•1000.

For G&L MFD pickups tested by Boscoe Music, the harness supports the factory-style four-conductor coil connections as well as the additional pickup shield/baseplate ground when present.

Pickup wiring has varied over G&L's long production history, so I recommend identifying an unfamiliar pickup by function rather than relying only on wire color.

The GLL1K may also be adapted to custom instruments using compatible four-conductor humbuckers, but pickup wiring and physical fit should be verified before purchase.

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L•1000 / L•1005 Compatibility

The GLL1K is designed primarily for:

• G&L L•1000
• G&L L•1005
• Custom instruments using L•1000-style passive electronics and a compatible four-conductor humbucker

Because G&L has used several body, control-plate and cavity arrangements over the years, I offer the GLL1K in four versions.

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Choosing the Correct Version

There are two things to choose:

1. Mounting style

Through-Body / Rear-Routed:
18mm-long potentiometer shafts with 9.5mm threaded bushings. Intended for controls mounted directly through the wooden body. These versions include the separate ring-terminal potentiometer grounding strap.

Control Plate:
15mm-long potentiometer shafts with 6.5mm threaded bushings. Intended for a metal control plate, including CLF Research-style installations. These versions do not include the separate through-body grounding strap because the conductive control plate normally bonds the potentiometer bodies together.

2. Potentiometer body size

Full-Size — 24mm bodies:
Recommended when installing in a genuine G&L body with adequate room for traditional full-size controls.

Mini — 16mm bodies:
Recommended for custom builds, non-G&L bodies, or any control cavity where additional clearance is useful.

The full-size and mini potentiometers use the same electrical values and sound the same. The difference is physical size, not tone.

If you're unsure which version will fit your bass, please message me before ordering. A photo of the control cavity is usually enough for me to help.

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What's Included

Every GLL1K includes:

• Complete prewired GLL1K harness
• 250kΩ Volume potentiometer
• 250kΩ Treble potentiometer
• 1MΩ reverse-audio Bass potentiometer
• Custom central wiring PCB
• ON-ON-ON Pickup Mode switch with custom PCB
• Prewired mono output jack
• Three push-on chrome knobs
• Mini screwdriver
• Self-adhesive neoprene insulating pad
• Required hookup wiring

Through-body versions additionally include the preassembled three-pot ring-terminal grounding strap.

Pickup and control plate are not included.

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Installation and Documentation

A detailed installation manual is available at:

boscoemusic com

The manual includes:

• installation instructions
• pickup wiring information
• Parallel / Single Coil / OMG explanations
• grounding instructions
• screw-terminal guidance
• troubleshooting
• complete wiring reference

Please take photos of your original wiring before disconnecting anything.

The screw terminals use internal box clamps, so after tightening a wire I recommend giving it a gentle pull to confirm that the conductor is actually captured inside the clamp.

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Why the GLL1K?

The L•1000 is one of my favorite examples of clever passive bass electronics. A single MFD humbucker, three passive controls and one toggle provide an unusually broad range of sounds without a battery or onboard preamp.

The downside is that reproducing the original harness by hand is surprisingly complicated.

I designed the GLL1K to retain what makes the L•1000 circuit special while making installation, troubleshooting and future servicing much easier.

If you have questions about compatibility or installation, please send me a message. I want your project to work and I'm happy to help.

Boscoe Music
boscoemusic com

Boscoe Music is an independent manufacturer and is not affiliated with G&L Musical Instruments. G&L, L•1000 and MFD are used here only to describe compatibility.