Switchcraft coil tap switch (left) and modern donor (right)

Rebuilding a Switchcraft “coil tap” switch for a Gibson ES-335

In the mid-70s, some Gibson semi-acoustics such as the ES-335 and ES-347 were fitted with coil splitting switches, which shorted out one coil of each pickup to provide a single coil sound. I think this was a nod to fashion as thanks to disco and in particular Nile Rogers, the Fender Stratocaster sound was all the rage.

The Gibson Schematic is here and as you can see it uses a special switch to split the pickup coils. This switch is as far as I know not available from Switchcraft. I had a customer come to me and ask me if I could get one for his guitar. I said no, but I can make you one. These switches haven’t really changed for over 50 years and thankfully it’s possible to take them apart and put them back together in different ways.

Here is the old switch. The problem with it is that the extension on the long leaf which the toggle acts against has broken off. The lower long strip of metal is a semi rigid stop meaning that the toggle can only move in one direction. I transferred this part (which isn’t present on the new switch) to the rebuilt version.

Old Switchcraft coil tap switch

Old Switchcraft coil tap switch

Here is the old switch together with a modern donor. The donor is the standard SPDT pickup switch.

Switchcraft coil tap switch (left) and modern donor (right)

Switchcraft coil tap switch (left) and modern donor (right)

I ended up using all the leaves from the new switch as they were straight with new contacts. There was no point using old, damaged parts for a misplaced loyalty to originality. Of course all the old parts will be given back to the customer as always so they can rebuild the original if they ever wanted to.

The only modification required was to bend the extension strip mentioned above the opposite way as on the pickup switch the contacts are inboard and on the coil split switch they are outboard.

Here is the new switch open and closed so that you can see the mode of operation.

Rebuilt Switchcraft coil tap switch open

Rebuilt Switchcraft coil tap switch open

Rebuilt Switchcraft coil tap switch closed

Rebuilt Switchcraft coil tap switch closed


2 Comments on “Rebuilding a Switchcraft “coil tap” switch for a Gibson ES-335

  1. Steve;

    Below is the second-part of a reply I sent (Nov ’15) to a guitar-playing friend of mine, when I emailed him the link to an Ebay ‘Buy it Now’ item in the US. The link directed you to a 1959 Gibson Les Paul electronics harness, the price being $18,500.00 – yes, that’s eighteen and a half grand.

    “… All of this was a result of searching for a half-decent wiring diagram for my 335 – hen’s teeth. There’s one that’s available from the Gibson site that I find irritating and disrespectful. I say disrespectful because it’s no more than a pencil-scrawl, by someone who’s comfortable with electronics. I’m not comfortable with schematics. I could never get my head round all those pyramid-shaped Earth symbols and long, straight lines going to curly things (pickups).Where are the labels? There are no labels, no wires, nothing that looks like my guitar. Gibson have made countless millions from ‘us’ over the decades and yet they can offer little more than a photocopy of a scrawled schematic. Do you know, I couldn’t even find, among the billions of sites, diagrams and schematics, what volume knob on my 335 is volume #1, and what is volume #2?
    Is volume #1 the bottom knob or the top knob? Is the bottom knob going to pickup #1 or pickup #2? Is pickup #1 the neck or the bridge? Nothing out-there that helps. Thankfully I’ve now stumbled-upon what volume is what and where it’s meant to go to. I’ve also stumbled upon – by plugging-in a lead and ‘tapping’ the pickups with a screwdriver – just where I’m supposed to solder that coil-tap switch that never worked.
    Yes, it’s that time of year again, when I have nobody in my house* and I get enough time to myself to address those jobs needing done but which are neglected for 10 months of the year.
    * I operate a guesthouse (KT)

    I bumped-into my 335 the other day, when I had to clear-out a room due to some damp. The 335 was plonked-down on one of my tables in what I call my ‘dining-room’, until I dealt with the damp problem with a sponge, a scrubbing brush and a bucket of hot-water and bleach – that was after I managed to clear the overflowing gutter, the source of the problem.
    Anyway, damp-proofing done and junk returned to the store room, I opened the guitar case and found the stramash of electronics just as I’d left them around this time last year. I’m not sure if I was expecting to open the case and suddenly find it had all ‘magicked’ together, just to be plugged-in and gigged/sold/hung on a wall. Well it wasn’t all magicked together, it’s all hanging-out and fucked-up and being neglected and taunting me, reminding me that it won’t assemble by itself. Anyway, I’ve progressed from where I was 12 months ago, I now have proper diagrams that I can understand, written notes to remind me (next year?) of what goes here and what goes there. I now have a clearer understanding of what I’m doing. I’m getting there.

    Back to the lack of a decent wiring-diagram source. I find it so frustrating that there are so many sites, experts and forums online but only a very basic Gibson schematic is what I can get my hands on. Sure, Seymour Duncan and others offer lovely diagrams in full colour, but not one of them offer a simple explanation ‘Wiring for Idiots’ that says; ‘This wire goes from the bottom volume knob to the such-and-such pickup’. None of them offer an explanation or diagram for my old ‘leaf-spring’ toggle – which wire goes where??? And, Seymour Duncan (SD) pickups have around 5 x wires coming from each, all colour-coded etc – this is no-good to me. Also, none of them make it clear if the view they’re offering is the view ‘from above and as I look at the guitar face-on’ or from the under-side of the pot – surely this would be considered basic? It leads me to a feeling of insecurity; “If I wire it like this will it all be back-to-front?”… Yes, I’m sure the information will be out there, but I can only search-through so many sites and forums before another hour has gone and I’ve seen the same SD diagram again and again. I would’ve thought the Gibson site would have everything, and I mean ‘everything’ necessary for undertaking a stock-repair of one of their thousand-buck instruments. Apparently not.

    It’s quite odd, when searching for ‘ES-335 w/coil-tap’, to see a picture of my leaf-spring toggle switch in there – and when I say ‘my leaf-spring toggle switch’, I mean it’s actually the one I have laying-around beside all my other Gibson bits. I’d sent that SD pickup for repair, oh, about 2 years ago now, and also sent the leaf-spring at the same time. The Manchester guy managed to repair the toggle switch and was proud enough of his efforts to feature this repair – with some pics – on his site, and as a result, my old leaf-spring appears whenever I do a search for ES-335 w/coil-tap. I never did offer thanks to the Manchester guy for his work, probably because I never knew if his work was good or bad. However, last night’s tinkerings have proven to me that his work has indeed been successful.

    Someday I’ll produce a proper wiring diagram – a work of art – that will offer essential reference to the half-dozen or so guys around the globe who own a Gibson ES-335 w/coil-tap.

    I’m almost at the soldering-and-assembling stage.

    Coffee time”….

    Steve, I’ll get back to you when I’ve undertaken the repair.


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