73-28 Bass

[rv_bass]

I decided to see if I can bring this 73-28 bass back to life. The bass is structurally in very good shape. Looks like there was a minor crack in the headstock that was repaired very well and is very solid.  If the front veneer did not show a crack it would be hard to see otherwise. The bridge pickup makes no sound and bridge controls appear non-functional, although I don’t know if it is the pickup, controls, or PF5 card.  The neck pickup has sound, volume, filters and trim pots work, the q is not original and not working properly and needs to be replaced (I have a spare new one in my parts box).  No RF noise issues. The five pin and 1/4 jack both work as they should.  So it is playable with the neck pickup and sounds great.  The hum canceling pickup was moved to between the pickups on the front of the bass and batteries moved to a routed compartment on the back, both mods reflecting the modern configurations. There are also screw inserts for the back plate and battery compartment, and I don’t know if the tailpiece is a replacement or original, it is wood with brass plate top.  The brass plate on the electronics cavity has a nice hammered pattern and will look nice once polished. Woods look like walnut top and back, mahogany body, walnut and beech/birch neck.  I spoke with Mica and she is checking with Ron for his thoughts on how to proceed.  I look forward to restoring the bass to full functional electronics again. A couple photos and a link to some quick clips recorded with an iPhone of the neck pickup. I will replace the roundwounds with flatwounds after a little cleaning and lemon oiling


https://app.box.com/s/kmtaeltvzkp98qb01bu9q3usn4mmufzd

[KR]

That's a worthy restoration Rob. Keep us posted.

[pauldo]

mmmm - that is delicious.   Hope that the refurbish goes well.

[edwardofhuncote]

   (all I got to say about that one...)

[David Houck]

Wonderful restoration project!

[JimmyJ]

Hey rv,

This is excellent news!  That bass was hanging there looking sad and lonely so I'm glad it's finding some love and attention.  It did feel nice in its raw state so I think it will be a winner once you've brought it back to life.  Best of luck!

Jimmy J

[KR]

Rob, did you plug the working neck pickup into the bridge pickup card input?

[rv_bass]

Keith, as you can see from this photo that Jimmy took when he examined the bass, everything is soldered to the PF5 card, no snap together parts.  So I have to think about how to approach this for a bit.

[rv_bass]

I did notice that the neck and hum cancelling pickup wires have two wires each soldered to the PF5 card, maybe a positive and negative (ground) wire for each pickup (?). The bridge pickup only has one wire soldered to the card, the second wire for that pickup is coiled around the wire sleeve.  It’s the wires extending from and coiled on the wire with the blue shrink wrap in the attached photo. Looks like the card has had a lot of secondary soldering done throughout it too.

[lembic76450]

Good luck, Rob.  As Keith said, a worthy restoration.

[KR]

Rob, indeed some difference with this one's pickups connections. Wonder what Ron thinks of these pics. I really hope that the connection is the issue with the bridge side of things.

[rv_bass]

Thanks everyone, it will probably take a little while, but we will see where it goes

[edwardofhuncote]

You just know somebody somewhere was totally baffled by what they found under that brass plate... and they were probably pretty good wiresmiths. No match for a Wire Wizard.


I'm betting this is going to be a happy ending. 

[JimmyJ]

Hey Rob,

I do believe careful removal of the shrink wrap I've circled (and arrowed) below will reveal mini-coax connectors.  A way to disconnect and swap pickup inputs.  That might be a good place to start.

Also, I think that roughly soldered wire wrapped around the bridge pickup's wire might be connected after all though I can't tell by the picture.  Those p/u wires are tiny shielded cables, like mini-guitar cables.  A single conductor in the center with a woven shield wire around the outside, plus the clear plastic insulation.  It appears they lost the shield connection to the board at some point and wrapped & soldered wire this wire to the sheild to make the connection.  Might not have been a successful hack though.

Keep us informed.  Exciting!
Jimmy J

[rv_bass]

Thanks, Jimmy, I will investigate and give that a try, -Rob