So, in a previous post ages ago, I showed the pickup change of my Supro Dual-Tone. The original guitar is shown to the right. This time around, I replaced all the internal electronics; potentiometers, capacitors and wires. I left the output jack and three way switch intact.
My thought behind this was that I know nada about guitar electronics, so it is really difficult for me to search out exactly the part that's bad and replace it. Chances are that I might actually damage the guitar in some way when doing that. But, if I remove almost the complete internal electronics and wiring, it would be easy of a skilled repair man to restore it (in worst case scenario).
Opening up the guitar.
This guitar is made of "reso-glass", a glass fiber of sort. So it actually is hollow inside, and looks something like this when it's opened:
The round things are the pots, on the upper part there are two pairs of volume and tone pots, one for each pickup. The left one is volume. On the lower side, you can see a major volume pot, three way switch and output jack. The black wires that come out of the wood beam in the middle are from the pickups. Below is a close-up for the volume and tone pot for the neck pickup. The cylinder is the cap for the tone pot.
New parts
So, since I don't know the reading on the caps and pots, I just took a plunge at some of the ones from RS guitarworks, since they had good reading. Took out what is normal pots for single coils, and ended up with 280K Ohm for volume, 250 Ohm for tone and two 0.015 microF (where are the Greek letters in here when you need them?) caps.
Anyway, below is a picture of the guitar with all the old electronics removed and three new pots in place.
And the all the new parts installed look something like this:
Doesn't look as pretty as the original, but it works and it's hidden inside the guitar anyway.
So, here is the guitar reassembled again. Doesn't look much different, only visible are the washers on the pots, hidden under the knobs and are only visible if you tilt the guitar. Could have used the old washers for that vintage look, but that's the kind of details only I and my therapist find interesting.
ConclusionI have a really good first impression of my repair. The volume and tone controls work. I might tweak the pickup height again and experiment with different values of the caps. But that is a project for later, 'cause I think I will be happy with this guitar as it is now. Won't even bother to find vintage replacement parts.
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15 comments:
You're really starting to rule at this. Do you notice much in the way of sound?
Also I TOTALLY think you should build yer own geetar, like a Tele or something
Also I TOTALLY think you should build yer own geetar, like a Tele or something
I been thinking about that. Even made drawings...
But, I wanted to get this done first. And get something more decent in the amplification department. Maybe a guitar build would be next winters project.
And yes, huge difference in sound. Methinks, anyway.
You've made drawings? As in wanting to build the body?
That'd be kewl - an actual custom-made axe rather than a kit.
...get a Line 6...you know you want it...
You've made drawings? As in wanting to build the body?
No, not that fancy. Although you can get body blanks that are planed and routed for neck and pickup. Just cut your own shape.
I just made a drawing with standard body shape and putting in different pickup configurations, bidges etc. Just to keep track of what parts needed and make an estimate of the cost and if I have the tools needed.
...but they already make Jackson King V's and Ibanez S & Jem...what more could you possibly want ? :-)
...but they already make Jackson King V's and Ibanez S & Jem...what more could you possibly want ? :-)
More spikes?
..a rev-meter like the one in Spinal Tap?
More necks, like Michael Angelo Batio favours?
I would appreciate your help. Just bought a Supro Ranchero hollowbody and the volume knob only works when just about totally cranked to top volume. There are no numbers on the knob, so I am guessing it is up near 8 when it starts working and is not all that loud. The only way inside to get to these is through the "F" holes and they are less than an inch wide. Any suggestions?
Perhaps I should find an electronics professional. Your opinion is valued.
Hi judysmountainbanjo,
sounds a lot like my Supro was. The overall volume isn't loud, is it? The Ranchero have only one pickup, with a tone and volume, right? So yours should be much easier to check. You could actually check if the reading on your pots are OK, but that requires you to dissasemble them.
However, I had really low overall output and the volume controll didn't do much. It was nearly on/ off (maybe it had some effect from 8 and up, as you said). Tone didn't do much, either. How is your tone control? All this is much better with new pots and caps.
If you go to a professional, then he should have no problem checking out the problem. If you're like me, who likes a bit of tinkering, it shouldn't be too difficult getting the pots out. Just take off the knobs (one screw on the side) and unscrew the pots (nut under the knob). You should be able to get the whole thing out the f-hole (taking off the pick guard will help). Your gutiar only have two pots (mine had five) so it should be easier to find the faulty part.
But let me again stress that I'm no professional. I just like poking around, and figuring out things. And the Supros are still relativly cheap, so it may not be worth spending much money on a professional.
Are you asking if I want to dismatle a fully functional, vintage guitar and sell off some hard-to-get parts? Sounds tempting... ;-)
Seriously, keep an eye out on ebay. They show up sometimes, but I might have to buy the whole swith selector. Supro, Valco, Airline and National all used the same plate.
There is a replacement on eBay, but I don't think it looks very good. For a replacement plate that looks like the real thing, contact My Rare Guitars, on their wbesite or on their eBay Store. They use the swith on their Eastwood line, which is a reproduction on old Supro/ Airline guitars. They do not currently list a switch on eBay, but I've seen them before, and I'm sure they can hook you up.
Btw, may I ask what guitar you are planning on using it on?
Anyway, good luck hunting down that plate.
the reason the old supros pots are all messed up is because the pickups came wired to the output of the pots, with the switch wired to the volume pots input. while this allows it to work in the maxed out position, the pot doesn't understand the send/receive when you roll it down, so what happens is that it will just cut out at a certain point on the pot, usually around 30%
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