L1000 - Bad wiring paths?

[billingsatx]

Ho gang - I'm looking into re-capping my bass. I wanted to make sure I got the correct values so I popped off the controls plate to bounce them against the block diagram schematic. I think I found a situation where someone did some kinda crappy work? I'm not sure. I've looked at as many schematics and pictures I could find, but would like some more expert eyes on this.

FWIW, best I can tell this is an 82/83 build (different dates on neck and body), and the serial is B006584.

Anyway, I'd appreciate any help. The pics are the entire control plat, followed by individual pots for (hopefully) a bit clearer shot of the work. Notice the solder mountain on the volume.

[Ken Baker]

Comparing your plate to this diagram, everything looks okay except possibly that orange cap on the volume pot. This would normally be 0.1µf (104K) 50v poly cap; the OMG cap that provides what is called bass boost (which is really a big treble cut). If that is its value, even if the voltage is off, it's okay. Clearly not original, which would be green in color like the one on the treble pot, but if it works you're good.

If I were to guess, a previous owner removed the original OMG cap because it introduces a little bit of single coil noise. Someone else came along and added it back in using that orange disc cap.

For instruments like a bass or guitar, there really is no need to replace caps because they rarely fail or wear out. These aren't the electrolytic caps found in amplifiers that usually do need replacement after many years of service. There is also no need to replace these caps with Sprague Orange Drop caps, as this is a bass and not a tube guitar amp. Orange Drops work well as capacitors go, but add no secret mojo tone in this context. They do add weight and their connections are a point of failure because of that weight.

Having said that, if you really have your heart set on re-capping it, here's what you'll need:

On the bass pot: 0.001µf 50v (that brownish cap) and 0.0022µf 50v (the green one)
On the treble pot: 0.047µf 50v
Between the volume pot and coil switch: 0.1µf 50v

Optional; on the treble pot: 6.8kΩ 1/4w 5% resistor

All caps should be poly. If poly isn't available for some of the values, a ceramic disc cap can be substituted. None of these parts are polarized. Source parts from Mouser, Digikey, or Newark.

Ken...

[billingsatx]

Thanks Ken. I think there were two things throwing me: 1) different color wires were used in a spot or two, and 2) the orange cap isn't on the switch. Looks there some jumpers in play as well, but yeah, once I looked at it again, it made sense. The cap isn't soldered on the switch, but could that was done to accommodate a different lead spacing. And the orange cap is a .1uf, but 500v

But it works fine - roll-offs are good, OMG kicks in. It does have a bit of single coil noise, but I can live with it - can't hear it on stage.

So excellent - i'll give it a good cleaning and leave it alone!
jeb

[derick]

The Chrome bridge and plates shouldn't go with a small hex pickup. The small hex poles were introduced circa April of 1982, just looking at the details I would guess a body date before November of 1981, but that isn't the case. The chrome bridges disappeared around B006800 and the smooth powder coat bridges started appearing October of '81, and chrome plates were phased out by February of '82, so this bass falls into the "never say never" category. If the neck has a 1983 date then it should be a bi-cut with no skunk stripe.

Either way, nice bass.

[billingsatx]

Thanks Derick. It does have a skunk stripe, so next time I have the neck off, I'll double check the dates. It's been a minute, so I may have them incorrect.

[derick]

To my eyes, the treble pot has a date code of 1378120. CTS pot, manufactured the 20th week of 1981. This is perfectly consistent with a bass manufactured in the summer/fall of 1981. The Chrome bridge serial B006584 would also be consistent with that timeline, but the small hex pickup and your body date of 82 or 83 doesn't match up with the "normal" manufacturing details. Also, I've never seen a mini-toggle that color on one of these early basses, and the tinning of the unused lug wouldn't have happened at the factory. Is there a rubber cap on the switch?

I'm saying, with no proof, that the bridge and control plate were transplanted from an earlier bass. The pickup would be correct for a 2nd quarter of '82 bass, or any bass made later than that up until the present day. Is the back plate chrome as well? I would be interested in the date stamp on the neck and body. None of this has much if any bearing on the value or usefulness of the instrument, but tracking these early manufacturing details is a hobby of mine.

[billingsatx]

Hey gang,
Just got a photo from the luthier doing a set up. Date stamp is Oct 2 1981. The back plate (assuming you're talking about at the bolt-on joint) is chrome. No rubber on the toggle either. Maybe a swapped out switch or it just fell off?

So maybe they scrounged a bit and used what was available? IDK. It plays great, and that's what matters most.

[Ken Baker]

Hey gang,
Just got a photo from the luthier doing a set up. Date stamp is Oct 2 1981. The back plate (assuming you're talking about at the bolt-on joint) is chrome. No rubber on the toggle either. Maybe a swapped out switch or it just fell off?

The little rubber switch covers just push on over the switch handle. You may be able to get a set of them from G&L, but it'll take a call to repairs.

So maybe they scrounged a bit and used what was available?

Entirely possible. Leo was notably thrifty in some areas. There were a few oddities back in the day that really do seem odd today but were normal then.

Ken...

[derick]

Okay, an October 1981 build would normally have had chrome plates and bridge like yours does, but a slotpole pickup. I'm saying that your switch and pickup have been replaced.

I do notice that the green wire from the pickup was soldered to pin5 on the switch, which is not factory. What behavior does that change?

[billingsatx]

It may have, but to be clear did you mean to say not a slotpole?. The green wire - looks like someone did some creative soldering. Instead of soldering to the pot, they went to the switch pole, and basically created what looks like a jumper with green wire instead of black. I don't know what difference it makes sonically or what behavior it affects as this has how I've always had it. I suppose I could de-sodler/re-solder per the schematic, but it works - so I don't see the need to fix what isn't broken (to me).

But then again, I don't have the depth of knowledge you do (no sarcasm intended - sincere complement), so if it is something that's a problem v. cosmetic let me know.