Wiring
Pick the voicing you're building and you'll get its bench-side wiring reference: the selector map, connection points, and the published harness.
This is the bench-side reference for the Relay Arc harness. It gives you the selector map, pickup locations, labeled connection points, and the published base wiring without turning into a full step-by-step soldering lesson.
Control Layout
5-Way Blade
Bridge
Retrotron Liverpool alone. The brightest, quickest Arc position.
Bridge + Middle
Liverpool and Dream 180 in parallel. Open attack with extra width.
Middle
Dream 180 alone. The main Arc voice.
Neck + Middle
Vintage 59 and Dream 180 in parallel. Wider and softer than position 3.
Neck
Vintage 59 alone. The warmest Arc position.
Volume - Standard 500k audio taper.
Tone (push-pull) - The published base harness uses the pot as a standard tone control. The push-pull switch lugs remain open until the Arc air contour is finalized.
Pickup Layout
- Bridge:
GFS Retrotron Liverpool, bridge cavity, main bright voice. - Middle:
GFS Dream 180, middle cavity, main Arc destination. - Neck:
GFS Vintage 59, neck cavity, warm supporting voice.
Reference Labels
| Label | Component | Wire | Description |
|---|---|---|---|
| BP-H | Bridge Pickup (Retrotron Liverpool) | red | Hot output wire |
| BP-G | Bridge Pickup (Retrotron Liverpool) | black | Ground wire |
| MP-H | Middle Pickup (Dream 180) | red | Hot output wire |
| MP-G | Middle Pickup (Dream 180) | black | Ground wire |
| NP-H | Neck Pickup (Vintage 59) | red | Hot output wire |
| NP-G | Neck Pickup (Vintage 59) | black | Ground wire |
| SW-BP | 5-Way Selector | Bridge input lug | |
| SW-MP | 5-Way Selector | Middle input lug | |
| SW-NP | 5-Way Selector | Neck input lug | |
| SW-OUT | 5-Way Selector | Selector common/output lug | |
| VOL-IN | Volume Pot (500k) | Input lug from selector | |
| VOL-W | Volume Pot (500k) | Wiper/output lug to jack | |
| VOL-B | Volume Pot (500k) | Back of pot, tied to ground bus | |
| TON-IN | Tone Pot (500k push-pull) | Tone input lug, tapped from VOL-IN | |
| TON-W | Tone Pot (500k push-pull) | Tone wiper lug to capacitor | |
| TON-B | Tone Pot (500k push-pull) | Back of pot, tied to ground bus | |
| TON-A1 | Tone Push-Pull Switch | Pole A, lug 1 - leave open in this revision | |
| TON-A2 | Tone Push-Pull Switch | Pole A, lug 2 - leave open in this revision | |
| TON-A3 | Tone Push-Pull Switch | Pole A, lug 3 - leave open in this revision | |
| TON-B1 | Tone Push-Pull Switch | Pole B, lug 1 - leave open in this revision | |
| TON-B2 | Tone Push-Pull Switch | Pole B, lug 2 - leave open in this revision | |
| TON-B3 | Tone Push-Pull Switch | Pole B, lug 3 - leave open in this revision | |
| CAP-H | Tone Capacitor | Hot leg from tone wiper | |
| CAP-G | Tone Capacitor | Ground leg to ground bus | |
| J-TIP | Output Jack | Tip lug (hot) | |
| J-SLV | Output Jack | Sleeve lug (ground) | |
| GND | Ground Bus | Common ground point for pot backs, pickup grounds, shielding, and jack sleeve |
Wiring Map
| From | To | Notes |
|---|---|---|
BP-H | SW-BP | Bridge pickup hot to bridge selector lug |
MP-H | SW-MP | Middle pickup hot to middle selector lug |
NP-H | SW-NP | Neck pickup hot to neck selector lug |
SW-OUT | VOL-IN | Selector output to volume input |
VOL-IN | TON-IN | Tone feed tapped from volume input |
VOL-W | J-TIP | Volume output to jack tip |
TON-W | CAP-H | Tone wiper to capacitor hot leg |
BP-G | GND | Bridge pickup ground |
MP-G | GND | Middle pickup ground |
NP-G | GND | Neck pickup ground |
VOL-B | GND | Ground the volume pot body |
TON-B | GND | Ground the tone pot body |
CAP-G | GND | Capacitor return to ground |
J-SLV | GND | Jack sleeve to ground bus |
Leave TON-A1 through TON-B3 open in this published revision. Those six switch lugs are reserved for the Arc air contour and are intentionally unused in the base harness.
Build Outline
Outline
Shield the cavity first
Apply copper foil before mounting any electronics. Arc is built for clean, spacious sounds, so noise control matters.
Wire the selector and pickups as the core harness
Build the full 5-way signal path first: pickups to selector, selector to volume, volume to jack, and the standard tone branch.
Finish the ground bus as a single system
Tie all pickup grounds, pot backs, cavity shielding, capacitor return, and jack sleeve into one ground scheme instead of creating scattered ground islands.
Bench-test before installation
Verify every selector position with a meter and a tap test, then install the harness in the body only after the output jack reads and sounds correct.
Sanity Checks
Checks
Continuity
In each selector position,
SW-OUTshould connect only to the lug or lugs for that position. Position 3 should isolate the middle pickup.Resistance
With volume full up, measure between
J-TIPandJ-SLV. Expect roughly 9.5 kOhm in position 1, 9.0 kOhm in position 3, and 8.0 kOhm in position 5, with the combined positions reading lower because the pickups are in parallel.Tap test
Plug into an amp at low volume and tap each pickup with a metal screwdriver. You should hear the expected pickup or pickup pair for every switch position.