Pickup Wiring Reference

Pickup Wiring Reference

Boscoe Music preamps can be used with a variety of pickups. This page provides wiring information for some common bass pickups and shows how to connect them directly to the PICKUP INPUT and GROUND screw terminals found on Boscoe Music preamps.

Important: Pickup manufacturers do not use a universal wire color standard, and wiring colors can sometimes change between models or production runs. Always confirm your pickup's wiring before making connections. If you're unsure, a multimeter can be used to identify the individual coils and verify the wiring.

Series vs. Parallel Wiring

Four-conductor humbuckers can generally be wired with their two coils in either series or parallel.

Series wiring connects the two coils end-to-end. This produces a higher-output signal with greater resistance and inductance and typically results in a thicker, darker sound.

Parallel wiring connects both coils directly between the pickup input and ground. This produces lower resistance and inductance and generally results in a clearer, brighter sound.

For the MMSR77 StingRay and MMSA78 preamps, parallel wiring is recommended when using a Music Man-style humbucker. The original StingRay and Sabre pickups used parallel coils, and the pickup's electrical characteristics are an important part of the interaction between the pickup and those vintage preamp circuits.

Music Man Style Pickups

Sterling by Music Man H-1 Ceramic Humbucker

Commonly found in Sterling by Music Man Ray4, Ray5, Ray24, and Ray25 basses.  These values are as tested on my personal pickups.  Note that they may differ on your bass, as SBMM have been known to change their pickup wiring from time to time.

Wire Colors

• Red — North (neck) +

• Black — North (neck) -

• White — South (bridge) +

• Green — South (bridge) -

• Bare — Ground / Shield

Series Wiring

• White → PICKUP INPUT

• Black + Bare → GROUND

• Green + Red → Connect together and insulate

Parallel Wiring — Recommended for MMSR77 and MMSA78

• Red + White → PICKUP INPUT

• Black + Green + Bare → GROUND

Many Ray4 and Ray24 basses are factory-wired in series. Rewiring a four-conductor pickup in parallel will more closely reproduce the pickup configuration used in the original StingRay.

Nordstrand MM4.2 / MM5.2

The Nordstrand MM4.2 and MM5.2 are vintage-style Music Man replacement pickups and are a good match for the MMSR77 when you're trying to reproduce the character of an early StingRay.  This information is from Nordstrand.  Please test your pickup before use.

Wire Colors

• Red — North (neck) +

• Green — North (neck) -

• Black — South (bridge) +

• White — South (bridge) -

Series Wiring

• Black → PICKUP INPUT

• Green → GROUND

• Red + White → Connect together and insulate

Parallel Wiring — Recommended for MMSR77

• Red + Black → PICKUP INPUT

• Green + White → GROUND

Note: The MM4.2/MM5.2 is built to vintage specifications and does not have grounded pole pieces. Depending on the bass and its shielding, additional grounding or cavity shielding may be helpful if you experience noise.

Aguilar AG-4M / AG-5M

The Aguilar AG-4M and AG-5M are vintage-style Music Man replacement pickups. The coils are internally wired in parallel, so only two pickup conductors need to be connected.  Information here comes from Aguilar.  Please test your own pickup.

Wiring

• White → PICKUP INPUT

• Black → GROUND

No additional series/parallel wiring is required.

The parallel configuration makes these pickups well suited for use with the MMSR77 when recreating a vintage-style StingRay setup.

Seymour Duncan SMB-4A / SMB-5A

The Seymour Duncan SMB-4A and SMB-5A are Alnico Music Man-style replacement humbuckers that can be wired in either series or parallel.  Information here comes from Seymour Duncan, please test your own to confirm.

Wire Colors

• Black — North (neck) +

• White — North (neck) -

• Red — South (bridge) +

• Green — South (bridge) -

Series Wiring

• Black → PICKUP INPUT

• Green + Bare → GROUND

• White + Red → Connect together and insulate

Parallel Wiring — Recommended for MMSR77

• Black + Red → PICKUP INPUT

• White + Green + Bare → GROUND

A Note About Vintage StingRay and Sabre Tone

The pickup and preamp in the original StingRay and Sabre were designed to work together, so pickup selection and wiring can have a significant effect on the final sound.

For the MMSR77 and MMSA78, a vintage-style Music Man humbucker wired in parallel will provide the closest match to the original configuration. A pickup with Alnico V magnets, approximately 1750–1950Ω DC resistance when wired in parallel, and approximately 700mH inductance is a good target.

Pickups wired in series will still work with either preamp, but the increased resistance and inductance change how the pickup interacts with the preamp. The result will generally be hotter and darker than the classic parallel-wired StingRay or Sabre configuration.  Note that this doesn't mean it will sound bad by any means - it's just something to take into consideration when selecting a pickup and wiring configuration.  Many customers have used the MMSR77 and MMSA78 preamps with different pickup types (Jazz bass, Precision bass, etc) with great success.

G&L Pickups

G&L L-Series MFD Pickup

Wiring reference for G&L Magnetic Field Design (MFD) humbuckers used in L-series basses.  Each coil should be around 4250 ohms (2125 ohms in parallel, 8500 ohms in series).  Tested on a L-2000 K-mod MFD.

Wire Colors

• Green — North (neck) +

• Yellow — North (neck) -

• Black — South (bridge) +

• White — South (bridge) -

• Blue — Ground (K-mod version only)

Series Wiring

• White → PICKUP INPUT

• Green → GROUND

• Black + Yellow → Connect together and insulate

Parallel Wiring

• Yellow + White → PICKUP INPUT

• Green + Black → GROUND

If your pickup includes the additional blue ground wire, connect it to GROUND as appropriate for your bass's wiring.

Installation Tips

Installation Tips

Complete all wiring before connecting the battery.

When using stranded wire with the screw terminals, lightly tinning the ends with solder is recommended to help ensure a secure connection.

Make sure all wires are firmly secured in the screw terminals. Lightly tinning stranded wire can make it easier to get a reliable connection.

Keep the bottom of the preamp insulated from conductive shielding paint, copper foil, or metal control plates where necessary.

If you experience hum or noise, verify the pickup ground, bridge ground, potentiometer grounding, and cavity shielding.

And most importantly, verify the wire colors on your particular pickup before connecting it. The information above represents the wiring commonly used for these models, but manufacturers can change specifications without notice.