Seymour Duncan STC-3P Bass Preamp - Part Two

◀ Part One

The STC-3P preamp had been wired up, and everything worked as it should. Tried fitting the circuit board into the control cavity, but the pickguard would not sit flush with the top of the body. I guess it was because of the massive bulk of the wiring getting in the way.

And so, it was time to carve out a new cavity just for the circuit board. I used my drill press with auger and router bits to gouge out a suitably-sized area. Cleanup was with chisels and my trusty rotary tool. Then, the cavity was shielded with conductive shielding paint. A piece of conductive self-adhesive copper tape was also added to ensure connectivity between the cavity shielding and pickguard foil shield. Once dry, I sealed the shielding paint layer with a couple coats of clear.

This new configuration meant that the circuit board would now be much further away from the pots; and I'd have to splice extra wire to each of the ten leads connecting the pots to the plastic connectors. Lengthening these hookup leads was a major headache in itself. To make sure I didn't get confused about what went where, I tackled only one lead at a time. Took me the better part of the night to get all this done.

Besides this, the battery compartment had to be modified to fit only one 9V battery. This was accomplished using strategically-placed and glued high density foam inserts. Tested the mod with an Energizer Max, and it was as "snug as a bug in a rug;" as my late Dad would say.

This time I was able to reinstall the pickguard with no problems, thanks in part to the judicious use of cable ties. Called up SUK bassist Jack Firdaus to give this American Deluxe Precision Bass V a whirl; and he was here in double-quick time. After all, he'd be the one using this bass; right? Once Jack had warmed up, he went straight into slap-and-pop mode. And guess what? I actually managed to record two short videos of Jack doing his thing straight into my Laney RB2. Uploaded them to YouTube, and here they are: Video One | Video Two.

Thanks for dropping by, and do enjoy the pics :)

Taming Noisy Pickup Polepieces

The pickup polepieces of the neck pickup on this 2004 American Deluxe Precision Bass V had, over time, begun to produce awful buzzy popping noise whenever someone accidentally touched them with his/her fingers; and it was getting to be too annoying to ignore. I believe this is quite a common problem, as it's been mentioned on various forums on the web. Relatedly, Audere Audio Engineering has come up with a very helpful and informative FAQ on this subject. Do take the time to read it as it answers many questions and offers a solution.

Upon disassembling both halves of the split P-style neck pickup, I discovered that the coils were completely unshielded; which might be a contributing factor to the problem. And, as the popping noise did not occur if you touched the polepieces while touching the strings or bridge; I was certain that the polepieces needed to be grounded.

To begin with, the pickup height foam strips were carefully pried off the underside of the pickups, exposing the bottom of the polepieces. As the strips had been attached with double-sided tape; there was some goo and gunk to be cleaned off with Zippo Lighter Fluid (naphtha).

Now that the pickup bottoms were clean, a strip of conductive self-adhesive copper tape was attached. A connection was established via a short jumper wire to the negative lug of the lower pickup; which was already connected to system ground. Yes, now the polepieces were well and truly grounded.

Next, the pickup coils themselves were wrapped with black pickup-coil tape; so that the windings would not come into contact with what was coming next. Following this was the next wrap of conductive self-adhesive copper tape. Another copper tape tab was soldered to the coil wrap, and this tab was soldered to the tape grounding the bottoms of the polepieces. In this way, any rogue interference would now be blocked and shunted to ground.

After thoroughly checking for continuity with a multimeter, the pickups were reunited with their plastic casings and reinstalled. Oh yes, I did also dab a thin layer of lacquer on the tops of the polepieces. Overkill? Well, maybe :)

Soon it was time to plug her in and let it rip. Guess what? The infamously noisy polepieces were now as quiet as mice when touched. Whew ... what a relief! So, guys and girls, you might want to try the steps I've outlined here if your polepieces ever start misbehaving. Last but not least, be excellent to each other and eat your veggies :)