Upgrading Tess

As a post-exam treat, I set about upgrading one of my guitars. My inner artist wanted something inspiring with more options. My inner perfectionist wanted higher quality and better technology. My inner poseur wanted something that looked “custom” but tasteful.

The guitar

“Tess” is an Ibanez GRGR121EX, acquired from a guitar shop in Abingdon. It’s available for about £150 online, but the shop price was £190. Given how variable quality is in this price bracket, this may have been justified for the privilege of checking it was not, in fact, a lemon. Then again, I was planning to replace most of the parts eventually anyway…

Ibanez GRGR121EX
Complete with EMG-style stock pickups and all-black hardware. The strap buttons have already been replaced with a locking system.

Machine heads

Tuning stability was not great on this guitar. In fairness, my reference point is my other electric guitar, which is made out of resin and so not susceptible to temperature or moisture. Nonetheless, I felt there was definitely room for improvement on the tuning system. I’ve been interested in locking tuners for a while, and also fancied a change from all-black hardware to a mixture of black and chrome. The guitar has a reverse headstock, however, which greatly limits the choice of affordable locking tuners. This is one of the less obvious drawbacks to a reverse headstock; you need left-handed hardware! (Or, if you prefer, this is a point in favour of reverse-headstock left-handed guitars.) In the end I got them from axetec, along with the other parts used in this project.

Locking tuners are beautifully simple in use. Simply pull the string through the hole, tighten up, and cut off the excess. Less winding means less slipping and stretching, as well as saving you a minute or so every time you change strings.

If you loosen the thumbwheel enough, it is possible to see the gearing in this system.
As the thumb-wheel is tightened, a rod pinches the string in the hole to prevent slipping. The excess can be cut off close to the hole.

Machine heads are typically divided into “sealed” and “open” designs; open tuners have an exposed mechanism and are easy to oil and maintain. They are common on acoustic guitars and bass guitars. Sealed tuners keep the mechanism tucked away from the elements, and in theory don’t need any maintenance. They are used on the vast majority of electric guitars, and many electric bass guitars as well as some acoustics. These locking tuners are an interesting case; they are generally sealed, but the mechanism is exposed when they are loosened for restringing. Best of both worlds? Worst of both worlds? Time will tell…

The factory tuners don’t have a visible screwhole; in fact they are built with two studs on the underside which sit into corresponding holes in the guitar headstock. This is quite an elegant design, and also meant that while I had to drill new holes, the old holes would at least be hidden by the new machine heads.

The factory tuners are relatively compact, and interface with two small holes to prevent twisting. These are completely covered by third-party tuners.

Drilling the holes for the new screws was a little intimidating, as the screws extended into about ¾ of the total head thickness. I used a hand drill with a 2mm bit. Thankfully the actual holes and washers for the tuners were all a standard size, so there was no difficulty threading the new tuners through.

Control Knobs

The original knobs are made of black plastic and feel cheap. I could also feel some drag when turning them, and procured new potentiometers, assuming that these were faulty. However, while fitting the new, shiny and reassuringly heavy telecaster-style knobs, I discovered the real problem; if the knobs float just above the body, they move easily. If they are set at an angle, or too close to the surface, they drag. So, if you’re finding odd resistance from your control knobs, get a screwdriver out and try mounting them 1mm higher. It may save you a few quid on new electronics you don’t need!


I must confess to some skepticism regarding pickups. It is difficult to understand why there is such a variety in the pricing of such a well-established and simple product. There really can’t be that much difference between the magnets and copper wire used in a £5 ebay pickup or Seymour Duncan’s finest, can there? Obviously the design is significant, and it is uncontroversial that pickup choice is one of the most significant factors determining a guitar’s tone, along with amplifier and playing technique. Still, I fancied something with a modern meaty sound, and some flexibility. I settled on a pair of Irongear Hot Slags with chrome covers. Definitely moving away a little from standard Ibanez territory here.

The Irongear Hot Slag is a high-output humbucker with a mids-heavy sound. These were nicely presented and ready for coil tapping and other trickery…

The factory pickups these are replacing are in a matt black casing evocative of EMG pickups, and strongly implying that they are active. In fact, these are simple passive pickups, set in a black resin which would have made rewiring the coils difficult.

The factory pickups are simple passive humbuckers, set in resin to add a little durability at the expense of tinkering

Unfortunately, they are also slightly smaller than the Irongears, and a buildup of resin around the base of the guitar neck resisted the insertion of a shiny replacement. After a little filing there was a sickening “CRACK” and small piece of resin came away, exposing more of the neck pocket. Once I’d started breathing again, I remembered that the neck is in fact held in place by four massive bolts, not a layer of resin, and that this was probably nothing to worry about. This created the needed space, and the guitar’s chrome content was increased accordingly.

*Just* too small

As is common for “upgrade” pickups, the Hot Slags provide separate access to each end of wire for each coil, as well as the cover grounding. This opened the way for some ambitious wiring schemes. I based the wiring on this design from the very helpful guitarelectronics.com, with an additional phase flip switch between the neck pickup coil selector and the main 3-way pickup selector switch. One note for those who wish to try this for themselves; I also had to swap the left and right sides of the coil-selector lugs to match the wiring on my own 3-way switch. Also, not all 3-way switches will work. 1728.com offers a fairly clear explanation of different kinds of switches and their use in guitar wiring.

Fiddly stuff this wiring. Horribly out of practice at soldering.

The most hair-raising part of the whole process was in fact drilling holes for the new switches. The guitar finish is fairly brittle, and drilling risked cracking and splintering the surrounding finish. For each new switch, I drilled a 3mm pilot hole from the inside of the cavity (to make sure there was room for the switch!), then, working from the face, removed more material with 4mm and 5mm drill bits. This would lead to 1-2mm of damage to the surrounding finish (if I was careful!), and from there I used a file to enlarge the hole to accept the switch. Unfortunately the switches are barely long enough to reach through the body; I intend to rectify this by removing a few mm of material from the inside with a pillar drill and large bit when I next have access to them. Still, the final result is neat and distinctive!

The top-most switch controls the phase of the neck pickup. The pair of switches above the tone knob switch each pickup between series, parallel and single-coil configurations.
£150 guitar + £100 new hardware > £250 guitar

Coming soon…

I’d like to analyse the actual differences this has made. It’s very difficult to choose pickups online, or in a shop for that matter, because of the lack of a baseline comparison. Soundclips are nice, but they tell you more about who has the nicest amplifier than who has the best pickups.

If you have any questions about this project, feel free to leave them as comments and I’ll try to get back to you soon!