Showing posts with label killswitch. Show all posts
Showing posts with label killswitch. Show all posts

Monday, March 13, 2017

Mavis Flying V Acrylic Guitar

The Mavis “Flying V” guitar featured today represents a first of sorts for me, because I'd never laid my hands on an acrylic-bodied instrument before this. I expected it to be unbearably heavy, but it was not. Frankly, if you’re comfortable with Les Pauls, you’ll be right at home with this Mavis.

Besides my initial reservations about the weight of this axe, I was also expecting it to sound thin and hollow. After all, tonewise, how could an acrylic body ever compare to one made of wood? However, as it turned out after rewiring and servicing, I was dead wrong. In a blindfold test, I’d expect to have a hard time distinguishing between the two. Now, I must admit that the V-shaped body makes playing sitting down rather uncomfortable. However, resting the crook of the V against one’s thigh solves the problem.

Sad to say, I could not find any information concerning this particular guitar on the web. I did, however, find out that “Mavis” is a house brand for Japan's Ishibashi Music Corporation. All said and done, this is a fine instrument loosely patterned after the Gibson Flying V Custom. The reader might also find it interesting that this rare gem was discovered in a used goods store in Cambodia, of all places!

This guitar sports a 24.75" scale 22 fret maple bolt-on neck with a rosewood fingerboard. Stringing is through-body, with a stylish chrome V-shaped face plate (think Flying V Custom) that the strings pass through before meeting a Sun Il tune-o-matic bridge.

Both pickups are humbuckers: a Select Model SEHG "Designed by EMG" (neck), and a Bill Lawrence U.S.A. (bridge). Controls consist of individual volume pots for each pickup, a 3-way toggle switch, and a coil tap for the Lawrence. Besides general setup and a string change, the owner wanted me to troubleshoot the wiring and components, and replace the coil tap with a kill switch.

Other than worn-out pots, gnarly soldering, and a corroded output jack; there were two major problems with this guitar. The first was that combining both pickups produced a thin, hollow sound, as if they were out of phase. The second was that on its own, regardless of whether the coil tap switch was engaged or not, the sound produced by the bridge pickup was weak and nasal. There was virtually no bass, but only upper mids and highs.

After time-consuming research on the web, I learned that the first (closest to the neck) coil of the bridge pickup was actually its south coil instead of north, and vice-versa. Bearing this in mind, I rewired the pickup "backwards," so to speak. Now, with both coils in phase and in series, the Lawrence was finally able to live up to its true potential. The difference was like night and day -- from wimpy and nasal to full and beefy, with nicely balanced highs, mids and lows. Totally satisfying!

Good for me, but I still had to solve the out-of-phase problem when both pickups were combined. As I’d already determined the correct wiring scheme for the Lawrence, the only solution was to reverse the wiring of the neck pickup. This solved the out-of-phase problem, but at the same time, introduced a new one. Now, since the ground and hot leads had been reversed, the body of the neck pickup itself was "live," resulting in an audible popping sound whenever I touched its height adjustment screws. Eventually, I was able to minimize this unwanted side effect by coating the screw heads with a couple layers of lacquer.

Having taken care of these problems, I proceeded to overhaul the entire control cavity, replace the faulty mini pots and output jack, and wire in a kill switch.














Monday, January 02, 2017

Ibanez RGIR27FE Iron Label 7 String Guitar

Is the art job on this particular RGIR27FE Iron Label stock? Nope, so you won't find anything quite like it in Bentley or eBay, for that matter. It's a custom job for the Pilgrims'/Achtung Riders' guitar player, who shall remain unnamed. Yes, it's all nifty sticker work, and not a paint job. Only the bottom half of the body and neck remain untouched. I have to admit that this is the first 7 string guitar I've ever played, let alone worked on. Imagine my surprise then, when I found myself happily strumming away (while carefully avoiding the low B string, of course) after just a few minutes. The neck, though wider than you'll find on a 6 string, is really comfy; for want of a better word.

Looks good, feels great, so what's the problem? Turns out the guitar would quite often go dead whenever the 3-way switch was in the middle and neck positions. All the electronic components checked out OK and the single 9V battery still had lots of juice. However, a closer look at the control cavity and output jack wiring revealed some pretty gnarly soldering as well as  burnt insulation. Ah, well ... let's deconstruct this baby, rewire it and see if that solves the problem. I'm glad to say that after rewiring the switches, 25K volume pot and output jack; this RGIR27FE sounds a whole lot better in all three positions.

The moral of this story is that you can equip your axe with the best components money can buy, but still screw it all up with a poor soldering job. Cold solder joints can fail at any moment, and burnt insulation can cause shorts when you least expect it (besides looking absolutely gnarly). Below you'll find some specs I found on the Ibanez website, followed by a couple of pics I took with my Zenfone 4. Enjoy :)

Origin: Indonesia
Neck: Nitro Wizard-7 3pc Maple/Bubinga
Body: Basswood
Fretboard: Bound Rosewood, 400mm Radius
Scale Length: 25.5"
Fretboard Markers: Side Dot
Frets: 24, Jumbo
Bridge: Gibraltar Standard II-7
Pickups: EMG® 707 Alnico Humbuckers (Active)
Hardware Color: Cosmo Black
Notable Feature: Kill Switch