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 :)

Seymour Duncan STC-3P Bass Preamp - Part One

Part Two ▶

Hallelujah! The Seymour Duncan STC-3P Bass Preamp is finally here. If you will recall, the store had earlier sent an STC-3M4, which would not work for the 2004 American Deluxe Precision Bass V electronics upgrade we've got planned. This one, thankfully, has got the features we need: Master Volume, Pickup Blend Control; and three-band EQ.

The Master Volume pot is a push/pull. Pushed in, it operates as a regular master volume for both pickups. Pulled up, the "Slap Contour" circuit is engaged; which, as the name implies, is an EQ preset specifically tailored to slap-and-pop techniques. Do note that the Slap Contour mid cut and bass boost can be "fine-tuned" by adjusting two trimpots located on the circuit board.

The bass/treble controls share one concentric pot; giving us a total of four controls. Now, if we'd gotten a preamp with separate controls for bass and treble; we'd have no place for the fifth pot as this bass has only four holes in the pickguard. I've hooked up the preamp to the pickups, and everything works as it should.

In the upcoming episode, we'll find out whether the pickguard can be reinstalled without any problem. If the new innards are too bulky to fit; we'll most probably have to enlarge or modify the control cavity. That's all for this post. Stay home, stay safe, and stay tuned; folks :)

Seymour Duncan STC-3M4 Bass Preamp

The bass player who wanted to upgrade his 2004 American Deluxe Precision Bass V had actually ordered a Seymour Duncan STC-3P Tone Circuit (onboard preamp). However, he was sent this "STC-3M4 Tone Circuit for Music Man Bass" instead. Which would be totally unusable as the STC-3M4 lacked a dedicated pickup blend pot; while his Precision Bass V had two pickups in a P/J configuration. In any case, since the box was already open, it would have been be a waste not to take some pics and share them with you; my faithful readers. Last I heard, the store had admitted their mistake and would be sending him an STC-3P. Stay tuned for updates :)

Epiphone Accu Bass Jr Overhaul

There was lots to repair on this Precision-style bass. For starters, the grimy fretboard had separated from the neck; and the nut was broken. The bridge was so cruddy that the saddle height hex screws were frozen in place. As if that weren't enough, someone had decided to "rewire" the electronics sans solder -- a couple connections were just twisted together! In any case, as I'd have to replace the pots and output jack and rewire the innards; that issue would be taken care of.

The fretboard was reglued to the neck with Titebond III and clamped, and all was well after four days. Following this, the fretboard was subjected to a thorough reconditioning; which included a healthy dose of lemon oil right at the end. I eventually managed to remove the frozen saddle height hex screws with the help of heat/cold treatment, and a sturdy pair of pliers. After derusting, servicing and a lube job, eight new hex screws were fitted to the saddles; and the bridge reinstalled.

The high density foam pieces that sat underneath the pickup halves had lost their springiness and were virtually unusable, these were replaced with four springs. All the electronics were removed; Alpha 500K pots,0.047uF cap, and Neutrik/Rean NYS229 output jack wired in.

After installing a new nut, the neck was reattached to the body. The Epiphone Accu Bass Jr was fitted with a new set of strings, and set up to normal specs. I'm thankful I was able to help give this bass a new lease of life.

Sunburst Precision Bass Copy LH

This instrument was a no-name left-handed sunburst Precision Bass copy that looked, felt and played like something much more expensive; I kid you not. However, as is to be expected from a Far East copy instrument, there was barely any shielding, and the electronics were of the el cheapo variety. The saddles were beginning to seize due to crud and rust, and the pickups could not be raised. As it turned out, the pickup height adjustment mechanism was two pieces of high-density foam that had lost their springiness over time. I knew I'd have to remedy that problem later.

Anyhow, it was time to get down and dirty. Once the stock electronics were desoldered, I shielded the underside of the pickguard with aluminium foil, and the pickup/control cavities with carbon paint. Following this, I wired in Alpha A250K pots, a Russian K40Y-9 PIO cap, and Neutrik/Rean NYS229 output jack. Meanwhile, the fretboard, which was gnarly and cruddy, had to be reconditioned; and the frets polished. As for the saddles, two of the height-adjusting hex screws were goners and had to be replaced.The neck angle was a little off too, but a teakwood veneer neck pocket shim managed to do the trick. Remember the pickups? Well, I removed the foam and installed four springs, one for each height-adjustment screw. Thankfully, I could now raise and lower the pickups with ease. Strung up with a fresh set of D'Addarios, set up carefully, and after a lot of spit and polish; this baby was eventually playing as well as it ever could.