A bass in need...

We are fortunate to count Paul Gagon as a member here, so it seemed natural to give him a home to stretch out in and relax a little. Maybe exercise the grey matter and present a little history of the guitar and bass (amps too!) from his perspective as one of the eminent designers of our time.

Got questions? Great! Good questions might be, "What are the EQ mappings for the M Series preamps?" Or, "What was the thought process behind the MJ-4?" Troubleshooting questions should remain in the regular forums (he reads those too). Finally, please be mindful of how I feel about tech questions via PM or email.

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A bass in need...

Postby Alex83tele » Tue Jan 10, 2017 11:23 am

Hi, I'm new to G&L, as far as "looking under the hood" goes. I've recently become very involved in making, modifying, and repairing electronics. So naturally, when the band I share a practice space had amp trouble, they came to me for help. After repairing the amp, I asked about the buzz coming from the bass...they asked if I could fix it...here we are. This bass wasn't modified, it was massacred. This is the condition the current owners obtained it in, so retribution is out of the question :roll: I won't get into the laundry list of atrocities committed on this poor instrument, but suffice it to say, whoever sanded it down to bare wood was courteous enough to leave MOST of the logo on the headstock. It reads "L-2000 Bass Series." The stamp on the bridge puts it in 1981 area, and I believe it. The areas that aren't normally visible show age, ie: the underside of the pickups, in the body cavity, and the little sliver of neck that faces the pickups. It has been wired, poorly I might add, like a PJ bass (V,V,T). The preamp...gone, 4PDT...gone. I would post pictures, but I'm afraid someone might see them during dinner and be sick.

While I work on convincing these guys to spend the money on getting this bass to its former glory (if in function alone), I also want to make it playable as quick as possible. I come to you in search of resources. I found the wiring diagram on the website (appreciated), but any and all info will be helpful. I like to learn as much as I can about an instrument when I'm working on it. Background on the instrument, company, etc, is all fascinating to me. I haven't found specs on the pickups yet. The neck pickup has a "4" written by hand on the underside. Are replacement covers for the pickups available? I'm just diving into this project, so forgive me if the information I seek isn't particularly hard to find. As I said, time is a consideration so I'm not waiting till after I've exhausted every resource to seek advice. If there is a more appropriate forum for a post like this one, please point me in the right direction. Thanks for reading.
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Re: A bass in need...

Postby Paul Gagon » Wed Jan 11, 2017 12:05 am

Alex83tele wrote:I come to you in search of resources. I found the wiring diagram on the website (appreciated), but any and all info will be helpful. I like to learn as much as I can about an instrument when I'm working on it. Background on the instrument, company, etc, is all fascinating to me. I haven't found specs on the pickups yet. The neck pickup has a "4" written by hand on the underside. Are replacement covers for the pickups available? I'm just diving into this project, so forgive me if the information I seek isn't particularly hard to find. As I said, time is a consideration so I'm not waiting till after I've exhausted every resource to seek advice. If there is a more appropriate forum for a post like this one, please point me in the right direction. Thanks for reading.

Hi Alex,
You came to the right place for help. This forum is full of a whole bunch of knowledgeable and great people. Let me give you some info about the pickups and electronics. The pickups are wound with 42 gauge magnet wire and each bobbin has 5,000 turns on them. There are some other posts in this section that talk about the pickups and the tone controls and how they interact. To get a good overview of the preamp, just go through the post in this same section on the G&L Bass Preamp rev 1.3. This will tell you about the preamp specifications and what the various components do. The preamp that was in the bass you're working on is of course much older but you will be replacing it with rev 1.3. Spend some time looking through the different posts on this forum. You will learn a ton of cool stuff about G&Ls. You will also get answers from many different players on this forum, all of which I have found to be extremely helpful and very eager to help.
Enjoy, Paul
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Re: A bass in need...

Postby Alex83tele » Thu Jan 12, 2017 10:13 am

Very cool forum indeed. Lot's of good information. A quick update: The neck pickup was buzzing loudly, and I discovered a severed wire on one of the coils. Even though it was the outer wire, and I was able to wrap it around the eyelet, alas, no luck. I'm now to the question of, do I recommend rewinding, or replacing (with the current G&L version) the pickup. Assuming the other coil is fine, is rewinding the one coil to match the specs of the other out of the question? Also, are there any practical considerations in replacing vs. repairing the pickup? I could see the new pickup overpowering the older one, but as of yet, I have have not done much work on pickups specifically. That may soon change after reading your story. Very cool of you to be on a forum like this, and communicating. We all have alot to learn from you. Thanks.
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Re: A bass in need...

Postby deltafred » Thu Jan 12, 2017 11:11 am

Alex83tele wrote:I was able to wrap it around the eyelet


I take it from this that you didn't solder the wire to the eyelet. If this is the case then the wire that you wrapped round will most probably be insulated with varnish so is still not making contact with the eyelet.

If you have no experience at soldering then rather than learn on such an expensive item I suggest you find someone who has the required skills and bribe them with money (or beer) to do the job properly.
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Re: A bass in need...

Postby Alex83tele » Thu Jan 12, 2017 10:02 pm

deltafred wrote:
Alex83tele wrote:I was able to wrap it around the eyelet

the wire that you wrapped round will most probably be insulated with varnish so is still not making contact with the eyelet.


I didn't outline the steps I took very well. I might be too concerned with "over staying my welcome," so to speak. My experience soldering covers most things, excluding pickup coils. It was just a matter of time, but I had no attempted to connect a coil wire until this project. After wrapping the eyelet, I applied some solder. I found a source that suggested the heat and the solder should effectively remove the insulation, and make contact. It did not. I then, very carefully scraped the exposed coil wire around the eyelet with a knife, and the insulation turned to dust. It seems the heat made it dry and brittle. I could see copper shining through, so I gave it another shot, making sure to drag some solder over the freshly exposed area. Still nothing. I have no doubt that in the right hands, this coil stood a better chance of being repaired, but I had to cut my losses on it. As far as I know, it might be severed in many places. Believe me, I love hearing other people's tips and tricks. It's just a matter of time before I'm building a coil winding machine :mrgreen: While I'm under the impression that the pickup needs to be rewound, I was trying take a tally of the pro's and cons of rewinding vs. replacing. I'm guessing a 35 year old magnet's properties have changed somewhat. My main concern is how they would pair up. Also, is it misguided to even consider having the single coil rewound, next to the original wound coil? I can see someone rolling their eyes at the thought, but then again, it's just wire. I don't know.
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Re: A bass in need...

Postby deltafred » Fri Jan 13, 2017 3:26 am

Thanks for clarifying.
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Re: A bass in need...

Postby Ken Baker » Fri Jan 13, 2017 4:33 pm

Alex83tele wrote:I'm guessing a 35 year old magnet's properties have changed somewhat. My main concern is how they would pair up. Also, is it misguided to even consider having the single coil rewound, next to the original wound coil? I can see someone rolling their eyes at the thought, but then again, it's just wire. I don't know.


Here's my 2 bits worth:

Yes, there will probably be some difference in field strength comparing your 35 year old magnets and new ones. However, any difference can usually be mitigated by adjusting pickup height and the pole pieces. So there's that.

If the broken coil can be successfully repaired with only a small loss in turns, do it. Any impedance difference between the coils will be so slight that you likely wouldn't notice any resulting single coil noise. However, if you end up having to rewind from scratch it would be better to have both coils done (and properly potted) so that you get a matched pair.

Ken...
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Re: A bass in need...

Postby Alex83tele » Sat Jan 14, 2017 8:34 pm

Ken Baker wrote:Here's my 2 bits worth:

Yes, there will probably be some difference in field strength comparing your 35 year old magnets and new ones. However, any difference can usually be mitigated by adjusting pickup height and the pole pieces. So there's that.

If the broken coil can be successfully repaired with only a small loss in turns, do it. Any impedance difference between the coils will be so slight that you likely wouldn't notice any resulting single coil noise. However, if you end up having to rewind from scratch it would be better to have both coils done (and properly potted) so that you get a matched pair.


Thanks Ken, it seemed logical, but it's nice to hear from someone who has had some experience in the matter. When it comes to pickup coils, I'm short on experience. Considering (1.) the cost of rewinding two coils, (2.) the condition of the magnets, and (3.) the condition of the pole pieces, I think replacement is the way to go. On to the next challenge! Total rewire on a budget. Yay!
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