|
| Previous: Back to Guitars | Next: Installing the Preamp |
Introduction
I went down to the local music store (Rondo) to check out the Ibanez GA5TCE for the second time in maybe a year. The GA5TCE is an unusual classical guitar: cutaway, reinforcing rod, 14th fret neck body joint, thin body, pickup and preamp, narrow neck. After playing it again, I was impressed with the sound, particularly since the body was so thin, but dissatisfied with the width of the neck at the nut, and decided against it yet again. I'd been looking all over town for a cheap classical that didn't sound too bad, a much more difficult task than that of finding a good sounding cheap steel string folk guitar it seems. All of the OK sounding classicals I played were at least $400USD, and the ones that actually sounded good were closer to $1000USD. Also, an internal pickup would be nice, but not essential. About to give up at Rondo, I spied a GA5 hanging on the rack. It played OK, sounded OK, and the workmanship on it seemed pretty good considering it was only selling for $120USD. The worker guy went in the back and got me a "fresh" one, which looked suspiciously slightly used right out of the box, but what with the cheap packing and the cardboard box it was hard to tell. Oh well, it spared me the heartbreak of putting the first ding in it! I also noticed a Belcat pickup / preamp combo hanging on a nearby pegboard for $30USD. "What the heck" I thought and had that thrown in as well, thinking that I would probably return it (but only after I'd had a good look at it).I liked the preamp and pickup enough to install them in the GA5. The pickup is a typical piezo, and as such it makes the bass strings sound a bit rubbery when played through an amplifier, but that is to be expected. You might think the "Presence" control is a midrange frequency sweep (what "presence" generally designates) but instead it forms the very highest band on this 4 band graphic eq. The eq control is adequate, though not spectacular. I'm glad the volume control is a knob, and not a slider. The entire package is absolutely fine for a $120USD guitar!
This series of pages describes that experience with pictures and text, and hopefully gives the experienced woodworker enough information to perform this install (or one similar to it) on his/her own. I wouldn't attempt this if your woodworking skills are limited, however - don't say I didn't warn you!
What's in the Box?
The Belcat pickup / preamp combo I bought has the hand-written number "EQ-7545R4" on it. It contains the preamp module, the pickup (with pre-wired plug to the preamp), the output jack (also with pre-wired plug to the preamp), and some miscellaneous mounting hardware.
Figure 2. Contents of the Belcat EQ-7545R4 preamp / pickup bubble pack.
Measuring and Installing the Pickup
The first thing to do is to determine if the piezo pickup is appropriate for this guitar. The one stocked in the kit appears to have the piezo lumps spaced somewhere between classical and folk (steel string) bridge spacing, so the outer strings on the GA5 are a little off center, but still solidly over the outer lumps. This is very important. There were no instructions in the box (!), but from photos of other pickups on the Belcat web page, it appears that the pickup wire goes on the bass side of the bridge. This puts the white mark on the pickup centered between the E and A strings.
Figure 3. Lay the pickup on the bridge to see if the spacing of the piezo "lumps" is OK.
Measure from left edge of bridge to the center of the pickup wire. Mark this location with a pencil, then use a sharp object (I like to use a 3" drywall screw) to indent the location as a drill guide. This should keep the drill bit from walking when you start the hole. Don't use a hammer to make this indent! Hand pressure should be enough.
Figure 4. Drill hole for pickup wire. You might have to elongate the hole side to side with a small file in order for the plug to fit through.
Start off drilling a small hole, then work your way up to the final diameter using gradually larger drill bits. I think the finished diameter on my GA5 was 1/8" or so. If the hole diameter is larger then the slot, then you will see some evidence of it even after the saddle is replaced. So if you find that the pickup plug needs a hole that is larger than the saddle slot, use a file once you get to this point and do some side to side elongation instead. Don't force the pickup wire through the hole.
When done drilling / filing, remove any burrs that exist around the hole you drilled, and remove any debris in the slot so that the pickup will sit absolutely flat against the bottom of the slot.
Initial Testing - Do You Like It?
At this point you should place the saddle back in the slot on top of the piezo pickup, plug the pickup into the preamp, plug the jack into the preamp, put in the battery, re-string the guitar and play around on it some through an amplifier. If you hate what you hear/see/feel, you can always take everything back apart and return the preamp / pickup with no real harm done to either it or the guitar.
Figure 5. Testing the pickup to see if I like it. The stock saddle is simply resting on top of the piezo pickup at this point.
Modifying the Saddle
Now the plastic saddle needs to be notched out to accommodate the piezo pickup. You might also want to take this opportunity to lower the overall action of the instrument - I did, my stock GA5 came setup a bit high for my taste. The finished height from all strings to the 12th fret (center of string to top of fret) is now about 1/8", or 3.5 mm. Don't go any lower than this or you will likely get buzzing problems. My guitar has slight buzzing on the B string if I pick it hard, probably should have gone for 4 mm or so on all strings.
Figure 6. Measuring the height of the piezo pickup.
Measure the height of the piezo pickup in the saddle slot; this is the amount of material that will need to be removed from the saddle. Also measure the distance in from the sides of the bridge to the pickup. You want to make the notch approximately 1 mm wider than this on each side.
Figure 7. Filing the saddle to accommodate the piezo pickup.
The bottom of the notch that will rest against the top of the pickup needs to be pretty flat so that good contact is made between the saddle and the pickup. Otherwise, you may get some variation in response from string to string. The best way I found of doing this is to clamp the saddle in a vise so that the future notch bottom is flush with the top of the vice jaws. Mark the limits of stock removal with a pencil, then go to town with a standard file until the material is removed. Watch out you don't stress the remaining plastic tips, they can easily crack off if you get careless with the file. You should use paper or card stock in the vise so as not to scratch or mangle the saddle.
Figure 8. Scraping the saddle flat and smooth with a razor blade.
As a finishing step, use a single edge razor blade and scrape the notched area smooth and even with the top of the vise jaws. This will provide a good consistently flat contact area for the pickup. Scrape with the razor blade held perpendicular to the surface as shown in the picture. You aren't doing any blade-type cutting here, just scraping.
Fitting the Saddle
Now the saddle should be fitted so that it correctly seats on top of the piezo pickup. Expect to spend a certain amount of time adjusting things and getting them right to your satisfaction.
Figure 9. The notched out saddle.
Figure 10. Saddle in position. Note the small gap, which is essential for good contact at the ends.
There should be a small gap between the remaining saddle plastic and the bottom of the bridge slot. This allows the saddle to fully contact the piezo pickup at the ends. The gap shouldn't be too big, or it will be obvious to the casual eye that something odd is going on underneath the saddle. You want a functional yet unobtrusive setup working here.
Figure 11. Thump test for consistent response.
An essential final test is to connect everything back up to the amplifier and tap with your finger over each string position on the saddle. Hold the saddle down on either side of where you are tapping with your other hand so as to get good contact. The "thump" coming from your amp should sound essentially the same no matter what string position you tap on. If there is a marked volume drop or lack of bass for any particular position, remove the saddle and correct whatever is causing the inconsistency in mechanical coupling between it and the piezo pickup. The ends tend to be the most problematic here.
| Previous: Back to Guitars | Next: Installing the Preamp |