restore or rewire?


Epic Member
Not really a Warmoth topic, but hopefully someone can give me some advise anyway.
this is my first bass restauration, and it's a mess!

Would it be best to restore or just start over again with new parts?



That's quite the mess; judging by all the corrosion I'd start over...  I can't recognize what kind of bass that; valuable enough to mess with trying to source NOS parts?
I'd replace some of those parts for sure, but... is that a rotary switch?  You'll probably want to hold on to that but you can get nicer pots and a new jack.  Also is that black-and-plastic thingie a capacitor?  I've never seen anything like it.

Also shield the cavity.  Or do basses not usually have problems with hum?  I've never seen inside one, come to think of it.
it looks to me like a gibson ripper,  id get new pots and wire, and keep the pups, rotary, and black mystery thing,  i also suggest shielding in the pup and control cavities, basses often hum more than guitars.  i have low output jazz pups in my bass, and they hum when one is off, or at a lower volume, the only time there isn't hum is when they are at the same volume.

so yeah, shield it. 

side note, hipshot makes a replacement gibson bridge, you might want to do get one and do an a/b test.
added mass and what not mkkk added cost to.
they sell at list price from the factory, go figure, i'll try finding a dealer who carries it, it would probably cost about $80 bucks from a store.
Yes, it's a '72 Gibson Ripper.

I really don't know what the black mystery thing is either :)
can't even get the knobs of the pots.. hence the bits and pieces of pickguard.
This might help.

At least it'll give you an idea of how it's menat to be.
Here's what it did:

You already have the schematic link... pickguard  scroll down.
From what I can figure out looking at the internet the black thing is a "tone choke".  I gather it's some sort of low-pass filter, apparently an inductor, but that's all I can figure out.  It's labeled 70-442 on this schematic: 

I think what's going on is the .1uF cap filters out very low frequencies, the tone choke filters out very high frequencies, which makes the middle knob a mid-cut.

Dimitri can probably shed more light on this, but if I understand correctly, you can almost certainly keep the original, I doubt it has degraded at all if it's just an inductor.
it's definately an inductor, schematic shows it in series with a cap to ground, that's a notch filter! this is cool! you can try to test it, make sure there is continuity, there should be some resistence but there is no telling how much, even if there is continuity you may have shorted coils in side and with the amount of rust on the core ( the srew ) that is a probability. it apears to be two inductor side by side, probably in series and oposite wound to cancel any noise they pickup. i'd test the resistence of each side independantly and if the match farly closely they may still be good.

if you want to replace it bill lawrence sells his Q-filters, but they look diferent so only if you don't care about origonality. i'm sure gibson still makes some version of that too, the varitone on the lucile uses something similar.

i bet you can salvage the switch. it may be tricky to find an exact replacement, or you can get a 5-6 way and do some aditional thing with the wireing.

replace the pots for sure. and forget extra sheilding. i have none in a guitar with a p-90 and no issues.

good luck, this is a cool schematic, a bit unusual so don't expect just any repair guy to be able to do it right the first time. what you have looks to stray from the drawing slightly too. i noticed that the pot for the notch filter is between the inductor and the cap, not to worry though  it will work the same. just keep the pics for reference when you put it back together.
I've done some more looking and this indicates that the part is indeed two inductors in series... a humbucker!  :laughing7:  It also gives a value of 1H.  I found a value of 1.5H on a different bass schematic.  Something in that range seems reasonable.  If you shield the cavity a single coil should be fine, so you can probably just get a 1 and a 1.5H inductor from DigiKey or RadioShack or something, and try those and the original and keep whichever sounds best.
maybe digikey, i dought radio shack, maybe one side of an audio trasformer will have that much, i dunno. but i don't think they'll have an inductor or choke with that much inductence.
I checked, DigiKey has a 1H and a 1.5H, as well as much bigger and much smaller.  RadioShack doesn't have shit.
Thanks everyone for all the advise and the links! Really appreciate it!
I will keep the switch and the 'tone choke' and replace the rest!
the pickups are actually still in good shape!! so that is less to worry about :)
For what it's worth, Epiphone is making a "reissue" though it sounds like they may have changed up the electronics, which doesn't help you with parts:

I consider that to be one of the all-time great body shapes, it's similar to the Ernie Ball Steve Morse guitar, at least before they ruined it with a gaudy purple maple cap :toothy11:. I strongly suspect that because of the design period of the Ripper, the electronics are one of Bill Lawrence's concoctions, it wouldn't hurt to give him a call because he could tell you want to do if you're looking to duplicate the function. He was working with Gibson around the time they set up in Nashville and he designed the L6S too - he's big on inductors...

Just call Bill at 877-647-2651! Practice your German first! :help:
Cool... but like Dimitri said, check the choke for continuity... if you put it together and the mid cut cuts out the highs as well as the mids, or hums as you roll off the mid cut, the choke probably has a short and you'll need a new one.
haha thanks, my german is a little bit rusty, but I think I can still pull it off :)
I'lll email him first though ;)
ok, I am a bit ashamed that this took me over a year to finish.. but I still wanted to post the 'after' pics.
the wiring was quite a nightmare and had to get some professional help finishing it :)
it was all worth it though, and I returned it to the owner (well his wife) today..

It was really nicely buffed, but unfortunately the pink insides of the case crumbled all over it :(