Upgrading an inexpensive semi-hollowbody with P-90 sound
Issue 166 June 07, 2012
Minor investment, major upgrade
My customer, Nathan Moore, loves the way his Epiphone Casino plays, but he’s not so crazy about the sound of its pickups.
Nathan plays in a local band, Sport Fishing USA.
Talking after one of their gigs, Nathan told me the pickups in this Epi are considerably overwound. They don’t give him the P-90 tones he feels the guitar should have.
He wants to get that sound without sinking a lot of money into this guitar.
We discussed whether to rewind the stock pickups or replace them. Nathan wanted to switch to Golden Age P-90s – Parsons Street model.
They’d be perfect except that they’re soapbars, not mounted in dog-ear frames like his guitar’s pickups.
Lucky break:As it turns out, it’s pretty easy to transplant a Parsons Street into a dog-ear frame if the polepiece spacing matches the holes in the cover. Here’s how I did a quick P-90 transplant:
Out come the stock pickups
They were soldered to their covers, but a quick hit with a soldering iron broke the joint easily:
The bobbins unscrew from their metal frames
I removed the two screws holding the dog-ear frame to the bobbin and unsoldered the ground wire:
Parsons Street transplant
Two screws held the P-90’s bottom plate, too. I took those screws out, but didn’t remove the plate:
I left this plate on to show how simple this swap can be. Removing the plate would be no big deal: I’d just have to resolder a ground wire to the Epiphone’s dog-ear frame. But the P-90 screwed right onto that frame, baseplate and all. It fit tightly, with the metal plates establishing a good ground. Easy!
Now it's time to solder the cover back on. Using a couple of spring clamps to hold the frame tight to the cover, I reflowed the solder joints that hold the cover and frame together.
What about rewinding?
The Epiphone’s neck pickup was way overwound, reading over 12k on my multimeter! It sounded super muddy. Modern Epi P-90 neck pickups use a different string spread than the bridge pickup, even though vintage Gibson P-90's are the same string spread for both neck and bridge positions. This means we can't transplant a Parsons Street P-90 in this dog-ear cover. The polepieces wouldn’t match the holes.
The thing to do here is to rewind the stock pickup to get a more usable DC resistance. I cut the wire off the coil and broke down the parts. I underwound the coil with about 8,500 winds of AWG wire to give it more clarity and punch.
It came out right around the high 6k range; that’s a perfect complement to the 8k Parsons Street bridge pickup.
A little less power on the neck pickup has a balancing effect, since there’s so much more string motion at the neck position compared to the bridge.
The P-90 transplant and the rewound pickup dropped right back into the guitar. They look factory, but they don’t sound factory.
Since I had the guts out anyway, I took this chance to redo this wiring harness with vintage push-back wire, CTS pots and a Switchcraft jack.
Nathan’s stoked: his Casino is finally sounding the way it should. Rock it, man!