ES-339 Prewired Wiring Harness — Gibson & Epiphone

Prewired Wiring Harness for the Gibson & Epiphone ES-339

The ES-339 takes the ES-335's semi-hollow design — laminated top, back, and sides built around a solid maple center block — and puts it in a smaller body, scaled down closer to a Les Paul's footprint, while keeping the full 24.75" scale length. The control cavity is still an open, routed pocket with no rear access panel, so all 4 pots, the switch, and the jack go in through the f-hole, exactly as they do on the 335. The change is that, with a smaller body, the f-hole opening is smaller on many ES-339s, especially newer Epiphone "Inspired by Gibson" models. Be sure to measure the f-hole size on your guitar against the f-hole minimum width specification shown below. This harness is built as a single complete prewired unit and tested on our workbench first, so what arrives at your door is a pre-spaced assembly you feed in and mount. Two volume controls, two tone controls, a 3-way pickup selector switch, wiring diagram, and installation instructions included.

Every ES-339 harness we build uses the same premium components as our other semi-hollow harnesses, selected for reliability and tonal performance, wired 50s-style so rolling back the volume knob keeps your top end intact instead of turning dull, with a tone control that stays smooth and usable across its whole range. If your ES-339 shipped with Gibson's factory "Memphis Tone Circuit," this harness replaces it with the road-proven 50s wiring scheme using the time-tested point-to-point wiring instead of a printed circuit board.

Choose Your Tone Caps

Paper-in-Oil (PIO) or Orange Drop

Centralab Paper-in-Oil (.033uF bridge, .015uF neck) is our Premium build — cleaner, warmer tone for jazz and blues playing, with a bit of bluesy grit when you dig in and improved sustain. Both are built for humbuckers.

Orange Drop (.022uF bridge, .022uF neck) is our Classic-series cap — modern-style tone with full dynamic range and a bright, distinct sound, a straightforward step up from the stock electronics most ES-339s ship with.

Since both cap options wire in exactly the same way, swapping later is a cap change, not a rewire.

What's Included

• Four Bourns Pro Audio 500K potentiometers (coarse-spline, short shaft)
• Tone capacitors — your choice: Orange Drop (.022uF bridge / .022uF neck) or Centralab Paper-in-Oil / PIO (.033uF bridge / .015uF neck)
• Switchcraft or Centralab 3-way toggle switch, prewired with a black tip — gold-plated switch available as an upgrade
• Switchcraft 1/4-inch output jack
• Vintage-style braided Gavitt 22 AWG push-back wire
• Fully prewired harness assembly board, drilled to specs and tested before it ships
• Wiring diagram and installation instructions included

Specifications & Fitment

• Fits the Gibson or Epiphone ES-339
• Newer ES-339 models — especially Epiphone's "Inspired by Gibson" line — often have a narrower f-hole than a standard ES-335. Measure yours against the f-hole minimum below before ordering; if it comes up short, contact us — we have an option with a smaller-diameter potentiometer built for tighter openings.
• Knobs require an 18-tooth coarse-spline fit (replacement knobs sold separately)
• Each pot mounts through a 3/8-inch control-cavity hole. Offshore-made units are often drilled for 5/16-inch pots and will need to be reamed out to 3/8 inch
• Jack wire run is long enough to reach the edge of the body — 9" total, which includes 3" of extra allowance built in for guitars with the jack mounted at the end of the body
• Not sure what your guitar needs? Reach out through our Contact Us page before ordering

This is the harness's own build spacing — the same assembly board serves the ES-335/ES-339 family, so what varies guitar to guitar is your f-hole opening, not these numbers:

ES-335 or ES-339 — Which Harness Do I Need?

Both harnesses are built the same way on the same bench — same components, same 50s wiring, same PIO/Orange Drop choice, same gold switch option. The only thing that changes is which product page matches your guitar. The fastest way to tell them apart is body size: an ES-339 is noticeably smaller and closer to a Les Paul's footprint, while an ES-335 has the larger, more traditional semi-hollow body — same 24.75" scale on both, so it's not a neck thing, it's a body thing. Own a full-size ES-335, a Casino, or a Sheraton instead? See our ES-335 harness listing. Still not sure which one you've got? Contact us with your guitar's model and we'll point you to the right page.

Shipping & Build Time

• 5–10 business days to build before it ships — every harness is custom-built to order, not pulled off a shelf
• In-stock means we have the parts on hand to build yours
• Ships to your USA front door for free
• Tested on the bench before it leaves — every harness is 100% guaranteed, and I want you to be 100% satisfied

Frequently Asked Questions

Is this the same harness as your ES-335 listing?
Functionally, yes — same components, same 50s wiring, same cap and switch options. We split it into its own page because ES-339 owners search differently than ES-335 owners, and because the fitment notes (f-hole size especially) are different enough to call out on their own rather than bury in the 335 listing.

Why choose PIO versus Orange Drop capacitors?
It comes down to voicing, not quality — Centralab PIO leans warmer and cleaner for jazz and blues, with more sustain and grit when pushed. Orange Drop gives you a brighter, more modern sound with full dynamic range. Both are built for humbuckers and wire in identically.

Is the pickup selector switch part of the harness?
Yes — a Switchcraft or Centralab 3-way toggle, prewired with a black tip, comes on every harness. A gold-plated switch is available as an upgrade.

What size knobs do I need?
Coarse-spline, 18-tooth — we sell replacement knobs in that fit if yours don't match.

Will this fit my Gibson Memphis ES-339?
Yes. If your Memphis ES-339 shipped with Gibson's factory "Memphis Tone Circuit," this harness replaces it outright with true 50s-style wiring.

My ES-339's f-hole looks small — will this still fit?
Measure it against the f-hole minimum in the spec table above. Newer Epiphone "Inspired by Gibson" ES-339s in particular often run narrower than a standard ES-335 f-hole. If yours measures under that minimum, contact us before ordering — we have a smaller-diameter pot option built for exactly this.

There's no back panel on my guitar — how does this actually go in?
As one piece. We build and test the whole harness on our bench first, then it feeds through the f-hole into your control cavity as a single assembly — see the Workbench Note below for the technique.

What's the turnaround time?
5–10 business days to build, then it ships free to any US address.

Cheers,
Gary Standerfer / Tone Man Guitar