ThoughtFactory.CreateThought()

Ferreting around in a spare room/cupboard/garage/other junk storage area can sometimes yield a wonderful surprise. I recently re-discovered an old, broken guitar sitting in our spare bathroom (which has been totally stripped awaiting renovation for.. oh, about 2 years now, and is now serving as an extra large cupboard. But that’s another story); an Epiphone Les Paul Special II that I picked up for AUD200 back in 1999. It was the first electric guitar I ever played on stage, and even though it’s a cheap piece of junk it will always hold a special place in my heart.

Upon inspection it was clear that time had not been kind to the guitar. I had originally put it into storage after the nut broke next to the 6th string, effectively making the guitar useless in it’s current state.

Numerous other problems presented themselves, leading to a rather impressive list of ailments:

• Machine heads that were falling apart and would not keep the strings in tune.
• Broken nut, limiting the guitar to 5 strings
• Crackling tone and volume pots
• A loose input socket
• Weak sound from the pickups
• A noisy pickup switch
• Annoying hum indicating that the guitar was not properly grounded

Given that list and my eagerness to give a task a go as long as it seems interesting enough, I decided to attempt some modifications myself.

First, let me be very clear about something: I know absolutely nothing about guitar modifications, woodworking or electrics. If you’re after a guide on how to do any of this then check out the various articles I reference throughout the post. I did this because I was bored and wanted to find out how to do this sort of thing. The guitar I tried it on was broken anyway and I was fine with the prospect of breaking it some more. Ultimately I’d like to get good enough to make modifications to some of my more expensive instruments, but until that time I’ll settle for practising on guitars that are next to worthless.

If this works out well then I’ve got another two guitars that need physical repairs and another 3 that could do with shielding as well as having the grounding looked at. The cheap Yamaha bass I picked up a few years back suffered from a horrible hum when I’m not touching the strings, which indicates that it’s not properly grounded, so I’ll have to take a look at that, too.

The first thing I had to do was pick replacement parts. The machine heads were easy; I ordered a set of non-locking Gotohs. I’ve never tried locking machine heads, so I figured that I’d stick with what I know. The guitar has a fixed bridge, so it simply needs a decent set of machine heads to keep it in tune.

The nut was a different story. Normally I’d get someone to cut a new bone nut from a blank, but there was no way I had the time or patience to do that this time around. I also couldn’t drop the guitar off at a shop for any period of time, as I’d be putting all the other hardware on it myself so I’d need to have access to it.

I could have bought myself a blank bone nut and shaped it myself, but it looks like a long, complicated process that involves specialist tools, a well thought out plan and actual skill; none of which I have. Fortunately I was able to buy a basic graphite nut in the same profile as the original, broken nut. As long as it is the correct height you can usually get away with attaching the nut without modification. At most I’d be up for a little filing to lower the height slightly.

But what about the electrics? How do I get rid of that hum? How do I rewire the guitar? To the intarwebs!

There’s an excellent article on properly grounding and wiring guitars over at Guitar Nuts that caught my eye. The basic idea is to insulate, create a single path to ground and create a makeshift Faraday Cage. To accomplish this I would need some copper backed tape and a lot of guess work. Unfortunately the article is geared towards a Fender Strat style guitar, so there were still a few problems that I would have to solve.

Darrell Young over at Digital Darrell has an excellent article on replacing the pickups in the exact same model of guitar that I’m working on. When I do the actual modification I’m sure that I’ll be be referring to this with some frequency.

Unlike Darrell there’s no way I’m going to spring for authentic Gibson pickups given that this is the first time I’ve ever tried anything like this. Instead I’m looking at getting a pair of cheap Gotoh humbuckers. Gotoh themselves are better known for their hardware (floating bridges, machine heads etc. In fact, the machine heads I put on the guitar are Gotoh), but they make a range of cheap, relatively high quality pickups that are made in Japan and can be picked up for around AUD40-AUD50. I managed to find a wiring guide for Gotoh pickups online, so I can do some pre-planning to figure out what my circuit is actually going to look like before the pickups arrive.

In order to fix the noisy volume and tone pots I would need to replace them. A pot is basically a variable resistor that can be used to alter the signal coming from your pickups. There are two main levels of resistence used in guitars; 250k and 500k. You also occasionally see 1Meg pots. A high resistance pot will retain more of the high frequencies in the signal.

As a general rule of thumb, the 250k models are normally used with single coil pickups to avoid an overly shrill sound. Since I’ll be putting humbuckers into the guitar I’ll be going with 500k replacements.

Quite a few of the parts have arrived, and over the next few weeks I’ll slowly but surely be progressing with the modification. I’ll be taking plenty of photos, and will be uploading themto a set on my Flickr stream as I go. Next thing on my agenda: remember enough about electronics from high school to avoid electrocuting myself.