Newbie tech needs some guidance

[Heket]

I am thinking that soon I may like to mess around with pickups again in my SG and, flush from the success with my Squier, I thought I'd do it myself this time.

That was until I opened it up and remembered it was a PCB

Please could you help me identify what I would need to do to replace a pickup?

From this picture you can see what it's like in there. What surprised me is that the tech I went to obviously saw the plugs, said "screw that" and just soldered the pickup in place. I didn't know you could do that! I read all sorts of horror stories about people having to rewire their Gibsons or buy special (and expensive) crimping tools to fit their own plugs, when all you need is a couple of gobs of solder? The place on the PCB marked "bridge" is empty.

I can see one wire is on the volume pot, the other is down on the right hand 'foot' of the pot. Where does that connect to?

Can you also tell me what that wiggly silver thing does? It's attached to a plug that says "GND" so I presume that's the ground, but why does it have to look so crazy like that? Does it need to be touching the pickup wires?

Also, since putting the cover back on I now have a buzz. It doesn't seem to be affected by my touching any metal parts and it applies to both pickups. It's also possible that I'm imagining it and there was always a buzz that I selectively ignored.

Faced with all that in there I feel a little lost. With the PCB there I can't learn how the everything is supposed to be connected to the other bits!

Thanks for all help. I really want to do this myself and have it works afterwards.

 

[dbb]

I'm curious myself, as I'm ignorant of the newer wiring harness with that plug-in connection. Without seeing the underside of the pcb board I have no idea how it's really wired. I guess i could google it.

Honestly it isn't that hard to wire an old-fashioned harness, it's just a bit time-consuming first go-round.

 

[Biddlin]

I know Molex makes the appropriate connector,
http://www.mouser.com/ProductDetail/Molex/43645-0200/?qs=%2fha2pyFadujOQx0p4hyM%2ffTjYGzbbrlpDeyO%252bJyrjYyc7ABpyAKZxw%3d%3d.
Here's an Ebay link for some.
Pickup Connectors for Late Model Gibson Guitars with PC Board Control Module | eBay
Frankly, I would cut the old connector off with enough lead on it to splice into. That said you can follow the path the tech took, but those contacts melt pretty easily.
Biddlin ;>)/

2003 stock faded special

 

[SG John]

GND is ground.

I'm sure it's easy enough to bypass a plug. Just use an ohm meter to find out where each pin goes to. Your tech probably figured out which lug on the transformer was "hot", and solder the ground right to the pot casing. Personally, I'd buy a set of decent CTS pots, get rid of the printed circuit board, and rewire the whole mess 50's style. Just do an image seach for 50's Gibson Guitar Schematics, and you should come up with plenty.

The buzzing is being caused by the ground. Maybe, it's not soldered properly, or there is not a complete ground circuit between all the pots, switch, and bridge.

 

[Relic61]

If yours looks anything like this, it seems you could use the connector currently attached to the pickup wire by disconnecting it at the splice under that white heat shrink wrap and solder it up to your new pup. Or solder it up like your tech did so long as heat from the iron isnt going to damage things.

Or maybe just by a new connector! 2 of these on 'the bay' coming from Ireland are about 10 Euro.

Then again as mentioned earlier, I too would just prefer to install 4 good pots that actually read 500k and solder everything up solid. I would also highly recommend that you then spend some time experimenting with caps and settling on something that you personally find exciting and serves your taste. If you havent done that yet it is really a bunch of fun and time well spent as it always end up being quite enlightening as well.

Sometimes the learning & doing of new things for yourself ends up being an extremely rewarding adventure & almost as much fun as playing the guitar with that great sounding mod you did yourself and are finding so much satisfaction in. I can see ya now... like a little scientist with all your caps laid out, head lamp shining and wiffs of smoke rising up off your soldering iron as you perfect your new found talent! Hmm, maybe a future road of enterprise will be revealing itself here? It already sounds like you enjoy doing it.

Maybe you can put up a pic of the actual cavity area you are working with? I hate assuming...

 

[smitty_p]

Can you also tell me what that wiggly silver thing does? It's attached to a plug that says "GND" so I presume that's the ground, but why does it have to look so crazy like that? Does it need to be touching the pickup wires?

I'm assuming it is the ground lead from the bridge - not the bridge pickup, but the bridge, itself. Electric guitars always have some ground connection to the strings. This is usually done by grounding the bridge or tailpiece. On a Strat the ground is usually soldered to the spring claw.

On SGs or Les Pauls, the ground may be squeezed against one of the bridge or tailpiece bushings. On my SG, the wire comes up underneath the Bigsby and is clamped between the Bigsby and the guitar body.

And, yes, it has to be wiggly, because electrons like to travel through wiggly wires.

Just teasing! Seriously, my guess is that they just grabbed a wire and didn't bother to cut it shorter.

Actually, it looks like thse are pre-made harnesses, so stopping to shorten the wire would likely have taken too long,

 

[smitty_p]

I second what Relic said. Sometimes there's value in doing stuff yourself, even if just for the learning experience. The best luthier in the world had to learn, too. Experts in any field had to learn to become experts. They weren't born with that knowledge.

I'd also direct-solder a 50s wiring setup. I know why Gibson uses the PCB approach, though. It makes assembly a lot faster and the PCBs probably aren't even made by Gibson. They are probably OEMed by a third party with Gibson-stamped parts. This is done with entire guitars, too. You may be surprised to learn that the majority of guitars built in Korea, regardless of brand name, are actually built by Samick.

 

[Tony M]

I have to jump on that bandwagon too.
Get a new set of pots, capacitors and output jack.
Type pickup wiring diagram into your search engine
and choose the one that applies to your pickups.
(or just visit the Seymour Duncan site)
www.seymourduncan.com
Remove the circuit board.
Install a new wiring harness the old fashioned way.
This will do several good things for you.
1- Brand new harness.
2- No more circuit board.
3- New knowledge in your head.
4- New skill for you.
5- Wonderful feeling of accomplishment.
6- Etc.

Here is an example.

 

[Biddlin]

Does anyone know if the swap from circuit board to wire and pots requires extra shimming to accommodate shaft lengths?
Biddlin ;>)/

 

[Tobacco Worm]

Good point Biddlin. I got outta the business before Gibson started that PC board crap in their guitars so I have no idea.

 

[smitty_p]

Does anyone know if the swap from circuit board to wire and pots requires extra shimming to accommodate shaft lengths?
Biddlin ;>)/

If you put two nuts on a shaft, one on the top and one underneath, couldn't you adjust the nut height on the bottom to set the pot height to where it needs to be?

 

[dbb]

Good point Biddlin. I got outta the business before Gibson started that PC board crap in their guitars so I have no idea.

I'm glad I'm not the only one that hasn't worked on these. I was feeling lonely.

What electronic use is a PC board in a passive electronics guitar? I can understand if it had some active system, but not in this case.

 

[Tony M]

I'm glad I'm not the only one that hasn't worked on these. I was feeling lonely.

What electronic use is a PC board in a passive electronics guitar? I can understand if it had some active system, but not in this case.

It cuts production costs and widens the profit margin.

 

[Relic61]

I'm glad I'm not the only one that hasn't worked on these. I was feeling lonely.

What electronic use is a PC board in a passive electronics guitar? I can understand if it had some active system, but not in this case.

Well Dave in this case I'm thinking it is nothing more than ease of assembly which comes down to time is money. Plus now you wont need to hire workers with this skill set or train folks on how to solder up these pots, switches etc. No thinking involved this way. Just put Schtuf where it belongs, plug everything in & done. Nothing more than the dumbing down of the workforce so to say as there is less thinking & or skill involved putting things together this way. Probaly way more OSHA friendly too without those 'dangerous' soldering guns & toxic fumes. American over-regulation makes it very difficult & costly for companies trying to survive bro. I'm guessing this type of 'arrangement' solves a myriad of issues & potential problems for Gibson.

 

[Heket]

Wow, thanks for all the answers! I know the "easy" option would be to rewire the whole thing, and since it was first mentioned I'm getting a bit of an itch to get the solder out again. But this is a whole different animal than my Squier, this will take a lot more research, finding the best supplies and reading about other people's projects. Tony, thanks for that diagram, it's brilliant! Wiring diagrams can get me a bit confuzzled, but this is like a proper picture, I can easily follow that.

So, the harness is not soldered to a plate or anything, it's just all attached to itself with wires, yes? I see the ground wire (from the bridge) needs to be attached to the braid of a braided pickup, which is probably what I'll be getting (don't need 4 wires). I'm not sure about caps at all, I need to read up about them. At least fiddling with electronics is easier than fiddling with a Strat.

Can anyone help me with a good supplier for pots and caps and such in the UK?

Barry, could you not see the image in my first post? I showed a picture of the control cavity with everything in it. Didn't look nearly as neat as that picture you posted.

Biddlin, what's that about shafts and nuts? Where does the shim go? Is there anything I can look at inside the cavity to answer your question? Also sadly the only spare plug I have has been cut pretty close to the plug, so splicing is not an option.

By the way, I mentioned a buzz after I last looked in there, that's gone now, haha. Every time I open the back something happens. The last time I did it the bridge pickup stopped working, just for a bit. Enough for me to hear my SG say "Oi! Stop looking up my skirt!"

 

[Biddlin]

Pots come with different length shafts. When you remove the circuit board, you increase the depth of the cavity and the pot shafts would stick farther out of the front. Shims(washers/spacers) might be needed for a good height on the knobs. The locking nut arrangement should work OK, don't over-tighten and crack the finish or wood.
Biddlin ;>)/

 

[Heket]

Pots come with different length shafts. When you remove the circuit board, you increase the depth of the cavity and the pot shafts would stick farther out of the front. Shims(washers/spacers) might be needed for a good height on the knobs. The locking nut arrangement should work OK, don't over-tighten and crack the finish or wood.
Biddlin ;>)/

Ah! May I ask then, my good sir, which would be the best for my application? Long or short (assuming I get the option)? Also I haven't the slightest clue which caps to experiment with, any suggestions?

Oh also, I'm guessing for an SG I would need long leg pickups? They certainly looked long when I had to route my Strat to fit them

 

[smitty_p]

Ah! May I ask then, my good sir, which would be the best for my application? Long or short (assuming I get the option)? Also I haven't the slightest clue which caps to experiment with, any suggestions?

Oh also, I'm guessing for an SG I would need long leg pickups? They certainly looked long when I had to route my Strat to fit them

Most Humbuckers use a .047 microfarad capacitor, though I've seen some with .036 for a slightly warmer sound. Strats typically use .022 microfarad caps.

 

[dbb]

It cuts production costs and widens the profit margin.

Well Dave in this case I'm thinking it is nothing more than ease of assembly which comes down to time is money. Plus now you wont need to hire workers with this skill set or train folks on how to solder up these pots, switches etc. No thinking involved this way. Just put Schtuf where it belongs, plug everything in & done. Nothing more than the dumbing down of the workforce so to say as there is less thinking & or skill involved putting things together this way.

Somehow I thought so.

In other words, no GOOD reason in terms of the guitar itself.

 

[Biddlin]

My Faded Specials use the shorter shaft .

These 500K CTS pots are in one of them. I use OEM .47mf caps. Some of my clients opt for .36 for warmer tone.
Biddlin ;>)/