# Music Man pickup, 3-way blade parallel/split/series Canonical page: https://guitarwiring.app/wiring-diagrams/seymour-duncan/music-man-three-way-blade-parallel-split-series Music Man humbucker · 3-way blade (parallel / split / series) · 3.3k resistor · Output to an active preamp Seymour Duncan sheet: a Music Man bass humbucker's four leads on a 3-way blade giving parallel, split and series, with a 3.3k resistor. The blade's output goes to the GRAY input wire of an active preamp that is not drawn. Drawing: https://guitarwiring.app/wiring-diagrams/seymour-duncan/music-man-three-way-blade-parallel-split-series.svg (back of controls) ## Parts and values - Music Man pickup: Music Man pickup (Black, White, Red, Green & bare); generic (Humbucker (four-conductor, Seymour Duncan colours)) - 3-way blade: 3-way blade switch; compatible example (CRL 3-Way Blade) - 3.3k resistor: 3.3k resistor; 3.3k; compatible example (3.3 kΩ Resistor) - Preamp (off the sheet): 'Connect to GRAY wire from preamp' / 'To ground'; generic (Off-board Preamp (input side)) ## Specific to this wiring - Title: MUSIC MAN \| 3 WAY BLADE DIAGRAM. - Legend: Parallel/Split/Series switching using a 3-way blade switch. Position 1: Parallel. Position 2: Split. Position 3: Series. - The sheet draws only the pickup and the blade. The blade output is labelled 'Connect to GRAY wire from preamp' and the ground wire 'To ground'; no pots, jack or battery are drawn. - OFF-SHEET PREAMP, IDENTIFIED FROM ANOTHER SEYMOUR DUNCAN SOURCE: Seymour Duncan 'MUSIC MAN Replacement System' sheet, https://www.seymourduncan.com/images/wiring-diagrams/MM\_Standard.pdf, saved as docs/wiring-diagrams/handoff/online/seymour-duncan\_WD\_MM\_3B/MM\_Standard.pdf, labels the joined pickup hot 'GRAY (input to preamp)' running into the preamp board's input connector, with the pickup's grounds on the control ground. So 'GRAY wire from preamp' is the preamp's audio input lead. Both off-sheet endpoints are modelled with the generic off-board preamp input part (input and ground). - Blade upper row, left to right: White; Green & bare (plus a loop to the next lug and the wire 'To ground'); the loop and one leg of the 3.3k resistor; the resistor's other leg and a diagonal to the lower row. Lower row, left to right (after a mounting hole): Black and the wire to the preamp; empty; the diagonal from the upper row; Red. - The blade's lugs are not labelled. Each row is mapped as one pole with its common at the end diagonally opposite the other row's (upper-row left lug with the White, lower-row right lug with the Red), and the remaining three lugs of each row read from the same physical end as positions 1–3. With that map the drawn wiring gives the printed legend in every position; the sheet does not mark which lever direction is position 1. - IMPORTANT NOTE FOR BASSES WITH A 3-COIL PICKUP (printed): If you are replacing your stock Music Man pickup with a Basslines Music Man replacement pickup, and your Music Man had three coils (with a third coil located on the center of the underside of the pickup), then you MUST use our 3-coil replacement pickup. A 2-coil standard Stingray pickup will NOT work as a drop-in replacement for a stock, 3-coil pickup. 3-coil pickups are found mainly on Music Man Sterling model basses, and on 90's era (or newer) 5-string Stingray models). - Value printed: 3.3k resistor. ## Connections 1. Pickup Green → Blade upper row, second lug (T1) (wire, green): Pickup Green (labelled 'Green & bare') to the upper row's second lug. 2. Pickup bare → Blade upper row, second lug (T1) (shield, bare): Pickup bare (drawn grey beside the green) to the same upper-row second lug. 3. Blade upper row, second lug (T1) → Ground (off the sheet) (wire, black): Wire from the upper row's second lug down past the blade, labelled 'To ground'. 4. Pickup Black → Blade lower row, first lug (T5) (wire, black): Pickup Black runs under the blade to the lower row's lug second from the left (first lug after the mounting hole). 5. Pickup White → Blade upper row, left lug (common T4) (wire, white): Pickup White to the upper row's left lug. 6. Pickup Red → Blade lower row, right wired lug (common T8) (wire, red): Pickup Red arcs over the whole blade and back to the lower row's right-hand wired lug. 7. Blade upper row, second lug (T1) → Blade upper row, third lug (T2) (wire, black): Black loop jumper from the upper row's second lug over to its third lug. 8. Blade upper row, third lug (T2) → 3.3k resistor (wire, black): One leg of the 3.3k resistor to the upper row's third lug. 9. 3.3k resistor → Blade upper row, right lug (T3) (wire, black): Other leg of the 3.3k resistor to the upper row's right lug. 10. Blade upper row, right lug (T3) → Blade lower row, third lug (T7) (wire, black): Diagonal black from the upper row's right lug to the lower row's third lug. 11. Blade lower row, first lug (T5) → Preamp input (GRAY wire, off the sheet) (wire, black): Wire straight down from the Black's lug, labelled 'Connect to GRAY wire from preamp'. ## What each position does - Position 1: Parallel: No pickup reaches the output. Source: Position 1: Parallel. Hand trace: Red joins Black at the preamp input, White joins Green at ground. - Position 2: Split: No pickup reaches the output. Source: Position 2: Split. Hand trace: White to ground, Red on the empty lug; only the Black–White coil is live. - Position 3: Series: No pickup reaches the output. Source: Position 3: Series. Hand trace: White joins Red (series link), which also goes to ground through the 3.3k resistor; Black to the preamp input. - The preamp is off the sheet: the board ends at a generic off-board preamp input, so there is no jack or volume and the engine does not analyse the positions (rule outputPresent). - Expected states are a hand trace of the drawn wiring against the printed legend, not an engine reading. - seriesLinkIsolated needs the per-position engine reading to accept the parallel (position 1) and split (position 2) link states; with no jack that reading is empty, so the rule fails there. In position 3 the series link also goes to ground through the 3.3k resistor; the resistor's effect on the series tone is not modelled. - The Music Man pickup is modelled by a generic four-conductor humbucker; which coil the split keeps is not identified on the sheet. - Pickup resistance is not specified, so no numeric meter readings are given. ## Check before plugging in - Position 1: the preamp input wire reads Black and Red together; White and Green read ground. - Position 2: Red reads open; the preamp input reads one coil. - Position 3: White and Red read joined, and 3.3k to ground. ## Source Tinkercaster's own drawing of the Seymour Duncan diagram WD\_MM\_3B, revision 2. Not the manufacturer's artwork and not endorsed by Seymour Duncan. See also [all wiring diagrams]().