Revitalising a 1979 Gibson "The SG"

[TZK321]

Once I gain the confidence I think I'll overhaul everything: pots, capacitors, output jack and anything else I can find.

[fender3x]

Gibson is not alone in having made pot/cap choices that seem odd...but Gibson seems to have used a lot of 300K and 100K pots with humbuckers. I don't know why, and the explanation of limited quality control may be the reason. It was easier to get pots that are unusual values then than now, so my guess is that somebody was experimenting, decided they sounded good and ran a series of them.

[TZK321]

What do you think of these capacitors?
https://www.gibson.com/Gear/Capacitors/PCAP-059

I just noticed the price of these capacitors. There's NO WAY I'm spending 124 US dollars on these.

Gibson also sells a few different potentiometers:
500 k Ohm audio taper: https://www.gibson.com/Gear/Potentiometers/PPAT500s
Historic audio taper: https://www.gibson.com/Gear/Potentiometers/PPAT059
300 k Ohm linear taper: https://www.gibson.com/Gear/Potentiometers/PPAT300s

If I were to upgrade the pots on my SG which would I need? I'm a complete novice with electrical things. I have a lot of trouble visualizing and understanding what's happening.

[Simon Barden]

Personally, I think that caps like that are a complete waste of time and hugely overpriced. If you were making an authentic looking as possible '59 Les Paul copy, then you might be prepared to spend that sort of money on caps, though you'd probably want ones that had been aged and not ones looking brand new.

With a little time and effort you can make your own vintage style capacitors. Here's one way to do it in this article. https://guitar.com/guides/diy-worksh...on-part-seven/

But really, the type of capacitor has almost no affect on the sound. I won't say none, as different capacitors do have slightly different frequency response characteristics, but they only come into effect with the tone knob rolled down and it is very subtle. You'd probably notice more change by swapping your guitar lead for one with a different type of cable. Sprague orange drops are the caps I'd go for. Easy to get hold of, reliable, and with the ±5% tolerance versions, you know the cap value will be pretty much spot on.

I'd use standard 500k CTS audio taper pots with split splined shafts for all four controls. You won't need the long shaft versions; the standard/short ones fit in the holes OK with enough shaft poking through to get a nut and washer on. You'll probably find that there's an anti-rotation tab poking upwards from the body. Unless you feel like drilling a shallow hole in the guitar to locate the tab, just snap it off with pliers, it breaks off easily. https://www.allparts.uk.com/products...-knurled-shaft There are many other suppliers (Allparts reference number works for US site and Aus Realparts site).

Again, if you were making a '59 LP replica, then you'd go for the vintage taper pots. But standard log/audio should give a nice smooth reduction in volume when you turn down using a clean amp. Linear pots can be used for tone, but you only start to really lose treble with the knob on 3 or below. Pretty much all or nothing.

[TZK321]

One more question, Simon. I noticed you installed copper shielding in the switch cavity. Did this make a significant difference? I was under the impression that shielding was only necessary for single coil pickups.

[Simon Barden]

Shielding is certainly more important for single coil pickups, but I've come across several instances where shielding the city on a humbucker equipped guitar has cured noise issues. It will depend on how electrically noisy your playing environment is. In many you won't notice anything, but for those noisier environments, it can help keep things as quiet as possible. All very difficult to prove unless you do a before and after comparison though. But the world is getting electrically noisier, and guitar manufacturing really hasn't kept pace with the increase in EMI since the basic guitar designs were created of the '40s and '50s and are still reproduced today.

So if you can do it, it's a worthwhile and cheap addition. The owner of the SG provided me with copper sheet, but I normally use 30mm tape as it's cheap to buy on eBay or Amazon and one 20m reel will do many guitars. I actually prefer using the tape to the sheet as it's thinner and easier to fit into corners. If it does break, just stick some more tape over the gap. Just make sure it comes with a conductive adhesive.

It's also worth shielding the pickup cavities as well if you can. You'll need to run some wire between them to ground them all, but if you use a piece of thin bare solid wire, you can just use more tape to stick it down, so no soldering is required.

[TZK321]

I did a bit of searching and look what I found: complete harnesses for the Gibson SG. Perfect for someone like myself with limited soldering experience.


this one is by Emerson: https://www.amazon.com/Emerson-Custo...1CZBZQ0DY4W75E

This one is by 920D: https://www.amazon.com/Gibson-Epipho...ustomerReviews

Are these companies held in high regard?

[Simon Barden]

They look OK, and I think I've heard good things about those companies wiring harnesses before (athough I have no direct experience).

BUT, you have a "The SG", not an SG Standard (or an SG based on that). The "The SG" has a barrel jack, not a standard chassis jack socket, and the selector switch in a different place compared to an SG Standard, so neither of those two pre-built harnesses will fit. It is a DIY job, I'm afraid. Or find someone better at electronics and soldering than you are to do it.

Because the barrel jack needs to be fitted from outside the body, you won't ever get a complete pre-built wiring harness for your guitar, as the jack will always have to be wired up after it's installed in the body. Switchcraft still make the same barrel jack.

[fender3x]

They look OK, and I think I've heard good things about those companies wiring harnesses before (athough I have no direct experience).

BUT, you have a "The SG", not an SG Standard (or an SG based on that). The "The SG" has a barrel jack, not a standard chassis jack socket, and the selector switch in a different place compared to an SG Standard, so neither of those two pre-built harnesses will fit. It is a DIY job, I'm afraid. Or find someone better at electronics and soldering than you are to do it.

Because the barrel jack needs to be fitted from outside the body, you won't ever get a complete pre-built wiring harness for your guitar, as the jack will always have to be wired up after it's installed in the body. Switchcraft still make the same barrel jack.

I think Emerson uses CTS pots that have been stamped with their logo.

The common wisdom is that a cap is a cap. Leo Fender used cheap poly "chicklet" caps at G&L.

Sent from my ONEPLUS A3000 using Tapatalk

[ONSatan]

Fantastic read. Thanks!