Last Friday night, my friend Simon brought his Epiphone 335 over to the house for a bit of TLC. It had a buzz, he couldn’t figure out what was causing it and had become a bit frustrated with it.
It stems back to the fact that the original pickups that were fitted to it had been a little uninspiring and he’d acquired a set of fairly modern SG pickups that he’d had a shop wire in for him.
Unfortunately, the soldering job looked a bit like this:
These aren’t the actual pots but two I pulled from another Gibson that had been butchered with a soldering iron some time ago. I wish I’d have taken pictures on Friday, but I just didn’t think of it at the time!
Wires were twisted together into masses of unspecified solder joints, the solder was almost melted to itself, but the contact with the Pot body was poor, contacts were badly twisted and none of the wires were through the contact holes or had any real mechanical grip. More than one joint fell off just by removing the pot from the hole! It was a mixture of far eastern promise and local desperation!
My initial assessment was that the mess needed cleaning up and the joints remade. But that’s easier said than done on a 335. This is the ‘Ship in a bottle’ bit.
So at the outset, I made an important error. I know a lot of people (even in the guitar business) aren’t very good with soldering irons. But I assumed that the installer had put the wires in the right place. And to be fair, the pickups did ‘work’ – in that they made a sound which seemed fairly consistent with humbuckers in a 335.
I tested that the earths were consistent with a meter – no resistances that you wouldn’t expect. The covers had been removed from the pickups, and this is where I got that Friday brain fade and didn’t notice the obvious mistake.
So we rewired a lot of it, cleaned up the joints and put it all back together. And still it hummed. So, having run out of time on Friday evening I sent Simon away with it with the proviso that I’d have another look when I had parts in stock to do a proper rewire if it were required.
Pickup Wiring Guides.
As an installer, I see a lot of different pickups. The wiring for them isn’t universal. Original Gibson pickups only had one wire – a positive that was straight to the pot and the shield which was connected to the ground side of the pickup and was tacked to the pot body. Modern Gibsons often have two conductors plus the shield. The colours are green and black. Seymours and Dimarzios are almost opposite to each other in terms of colour coding, especially with 4 conductor units. Every time I install a pickup I look up the pickup wiring guide online if I don’t have the original paperwork.
Having had a rethink over the weekend I asked Simon to bring it back last night – I had a feeling that the shields on the pickup wires were the problem, acting as an antenna. They weren’t independently earthed, so I was going to earth them separately -and that’s when I noticed the mistake:
Green is NOT live on a Gibson Pickup (at least not these ones) – black is. The original installer had wired the pickups in backwards, making the shield of the pickup wire part of the signal path. I quickly checked my hypothosis by taking a piece of loose wire from the bridge to the chassis of the pickup – which removed all signal from the guitar to silence. We swapped the wires around and suddenly the noise was gone.
The take away:
Never assume anything. It was late Friday, I was a bit knackered, and I missed something incredibly obvious. Always check the wiring colours!!!
The Ship in a Bottle
The real trick with 335s and other similar guitars, is to have the entire wiring out on the top of the body to work on it. Getting it back in is then a choice between two methods. One is to use soft and over length wires to give you lots of room to manoeuvre it in – using plastic tubes through the holes in the guitar and back onto the spindles of the pots to draw it all back. The jack socket needs a plug in it that will go through the hole (usually by removing the case from the plug) to draw it back.
The other method is to wire the pots on a cardboard caddy that replicates the shape of the holes in the body with fairly stiff earth wire (and possibly the capacitor) running forwards from Tone to Vol on both sides. This way if your hand is small enough you can put the vol in near the hole, and that will guide the tone to the right spot. Use a soft wire to join the two tones together and to the socket, nicely long so that you can remove one side at a time.
Old farts like me will always have some old solder lying around for restoring older guitars. This stuff isn’t so readily available any more because of its lead content, and its not used on production items any more.
We’re allowed to use it (and actually to obtain it for repair work). It flows better and at lower temperatures than modern solder. You’ll find that working on a modern guitar requires a lot of heat when trying to unsolder a ‘big blob’ of earth where everything has been twisted together onto the back of a pot for quickness. It can make a quite a mess. For any tricky job I’ll use the old stuff to reduce the heat necessary.
Using a solder station with a temperature control can help, especially with lead free solder. But also, its really important when making the joint to make sure the solder ‘flows’ and not just sticks. Because the stuff requires so much heat now, I see a lot of joints that aren’t really well made. Be patient, you’ll see it flow when there’s enough heat. The wire will get very hot, so hold it with pliers where you can.
Always remove all the solder from a pot leg, using a solder sucker (they’re cheap enough), and make sure the wires go through the hole. This way you can use less solder to make your joint and it will flow more easily. Plus it then has a mechanical strength – important when you’re wrestling it back through the F- Hole of a 335!
Happy Ship building!