59 wiring for les paul

[brewdude]

[IMG467]http://i291.photobucket.com/albums/ll31 ... TAPERS.jpg[/img]

You can see the pots are NOT all the same. Whether you like them or not is another thing.

Am I misunderstanding the graph? It looks to me like the RS pot is nearly linear. I thought that volume pots were usually audio taper.

[amplifiednation]

Rs superpots have a nice taper. They advertise them as being over 500k but the ones I got were like 450. The turn loosens up as you use them. Short shaft for historics. Long shaft for stds and classics. Any audio taper will work. The pio caps are the best if you can find some nos. The repro bee caps are cool but I think you can get a better cap for the money. I like .022 for the neck .015 for the bridge. If you ever check out the lespaulforum there are tons of wiring diagrams on there

[Big Jim]

One of the biggest problem with a lot of modern les pauls is Gibson used linear taper pots . That combined with wiring the the tone control from the input to the volume pot instead of the output makes a huge difference. The new Gibson historic pots 500kA are some of the highest quality pots from CTS I have seen. Much better than what most sell. And if you are a real nut you can scrape the edges of the carbon track to bring them up over 500K.

CE Distribution has them, AKA Antique Electronic Supply,
http://www.tubesandmore.com/

Billy, I only saw the short shaft Historic pots on AES....Am I missing the long shaft version there?
Thanks Jim

[ampbldr2]

I had to see what im dealing with here. The original lp classic pots are about 3/4 in and are long shaft. Because they tie into this bridge plate takes about 1/4 in alone. I do not see being able to mount short shafts in the Classic LP and removing the plate. So now I need to find long shaft A500K pots. The tone pots were not impressing me in the readings either so i guess i will be ordering 4 pots instead of the 2 like i was hoping.

These were the measurements i got.
Bridge
V-251K
T-436k

Neck
V-259k
T-474k

[amplifiednation]

You need long shaft for classics and stds. Short shaft for Historics. If you are rewiring a non historic, pull the ground plate! You can get cts pots from anywhere, not just RS or AES. The tolerance might pull them under 500 though. Just measure what you get and put the higher valued pots as volume, lower as tone. you may even want to order some extras to have your pick from a few more. They arent that expensive, or get the rs supers and you should get a pretty high valued pot pretty consistantly.

[billyz]

One of the biggest problem with a lot of modern les pauls is Gibson used linear taper pots . That combined with wiring the the tone control from the input to the volume pot instead of the output makes a huge difference. The new Gibson historic pots 500kA are some of the highest quality pots from CTS I have seen. Much better than what most sell. And if you are a real nut you can scrape the edges of the carbon track to bring them up over 500K.

CE Distribution has them, AKA Antique Electronic Supply,
http://www.tubesandmore.com/

Billy, I only saw the short shaft Historic pots on AES....Am I missing the long shaft version there?
Thanks Jim

The Historic pots are for vintage style les paul control cavities, no long shafts. They also work for 335's SG's etc. Not the les pauls with the metal plates to attach the controls to. Sorry. unless you want to router your cavity to vintage specs.

If you are really worried about the values , I find it pretty easy to take them apart and scrape the edge of the carbon track to bring them up, even over 600K. You will be surprised at how little it takes to bring them up in value.

[vibratoking]

Am I misunderstanding the graph? It looks to me like the RS pot is nearly linear. I thought that volume pots were usually audio taper.

I don't like the plots for any of those devices. It should be audio taper.

BillyZ - As far as scraping pots. I tried to scrape a pot this weekend with an Exacto and with a very small jewelers file. It seems the file is a better choice. At one point, the file slipped and put a VERY, VERY small scratch in the top surface (the surface that the pot contacts ride on) of the carbon track. I MEAN SMALL! That imperceptably small scratch resulted in about 500k Ohms of resistance across it. Needless to say, the pot is now worthless to me. Good thing I used an old POS pot to begin with. Just to be clear, do you scrape the edge of the track or the top of the track? If scraping the edge, you have to be careful to leave the track wide enough so that the contacts make good contact. I could see that this might be another way to ruin the pot. I have another POS pot that I will be trying with sometime soon. The damage caused by a 90mph windstorm derailed my amp efforts this weekend.

[billyz]

Am I misunderstanding the graph? It looks to me like the RS pot is nearly linear. I thought that volume pots were usually audio taper.

I don't like the plots for any of those devices. It should be audio taper.

BillyZ - As far as scraping pots. I tried to scrape a pot this weekend with an Exacto and with a very small jewelers file. It seems the files is a better choice. At one point, the file slipped and put a VERY, VERY small scratch in the top surface (the surface that the pot contacts ride on) of the carbon track. I MEAN SMALL! That imperceptably small scratch resulted in about 500k Ohms of resistance across it. Needless to say, the pot is now worthless to me. Good thing I used an old POS pot to begin with. Just to be clear, do you scrape the edge of the track or the top of the track? If scraping the edge, you have to be careful to leave the track wide enough so that the contacts make good contact. I could see that this might be another way to ruin the pot. I have another POS pot that I will be trying with sometime soon. The damage caused by a 90mph windstorm derailed my amp efforts this weekend.

Well you do have to be careful. I use an exacto knife to scrape the edge very gently. Sometimes a slight angle helps. Also, Scrape the inside edge if you can reach it. Some pots come completely apart, others do not. I run the knife blade perpendicular to the carbon track edge, not parallel. I have never had to removed enough material to even be able to tell it has been done.

[rooster]

billyz et all - nice post. I like the graph thing, thanks for taking the time to do that, BTW, brewdude.

OK, so to billz first, AES stocks two Gibson 500K volume pots. Like you said, one is the Historic version on a yellow card, the other not. BUT - the thing is, the one that is not is also listed as "510K ohms", which makes me wonder if I heard you right? You said to buy the Historic version, right? I believe it has the Gibson part # --- - 059 on the card. Am I reading you right? Thanks in advance for clearing this up.

OK, as to the pot scraping thing, I am clear how you are suggesting to go about this, but I want to add some confusion to the issue and tell you how I do this 'scraping' thing. First though, have any of you considered this: If the carbon itself has value, say 500K, how does it INCREASE in value if you REMOVE material? This flys in the face of logic. eh?

OK, so if that works, awesome, and I don't need to understand it. My way, flying even more into the non-logical path, is to disassemble the pot, and very lightly (5 or 6 complete passes), sand, (using 600 grit black/wet or dry sandpaper), the FACE of the carbon track. Yeah, and then even more wrong it seems, I have wet this sandpaper with Deoxit first, and then spray clean the surface with Deoxit again when I am done.

Well, for me, this will increase the value of the pot by 15-20%. For example, a 240K pot will become 278K. OK, I end up with no scratchy pot, and it doesn't alter over time, FWIW.

But, finally, I am still at a loss as to why this works, or the other method, for that matter. With my method, I suspect that the carbon trace is polished by CTS or whomever, and this polishing process puts a surface on the carbon that conducts energy more easily. When I sand it, I rough up this surface and the resistive value of the trace goes up in value. Well, that's just my thought, no science to back it up. As to the other method, well, actually I did try it once or twice and got nowhere with it.

What you could do is hook up a DMM to the outside lugs, put the shaft/carbon trace in a vise and have at it, either method. You might see a change then. Yeah, OK, somebody do this while I play some guitar...

[paulster]

how does it INCREASE in value if you REMOVE material? This flys in the face of logic. eh?

Not al all. Think resistors in parallel, say 4x 2M2 resistors side by side in parallel. You'll have 550K. Then take one away, i.e. remove some of the resistive element. You'll then have 733K.

Or think how the resistance of a thick wire is lower than a thin wire.

Etc., etc.

[billyz]

rooster,
Think of it this way. You want to create more resistance. More or thicker carbon would be less resistance. Carbon is the conductor, and a pretty good one. So you want less carbon to further restrict the flow of electrons.

As for the method of removing the carbon, your method is perfectly acceptable, just be sure to take a very even cut off the surface. I prefer the edge method because that way I can avoid the track of the commutator. some carbon pads are very close to the edge and easy to scrape. But I have seen some that more inside from the substrate edge . You will have no affect scraping at the substrate, it is not the conductor. It is the insulator.

I have restored old vintage Wah wah pots that were noisey no matter how much I sprayed them, by polishing the commutator contact with 600 grit sandpaper and fader lube.

Now, the Catalog at AES or CE distribution is wrong. I have told them several times about the 510K and 530K descriptions of the Gibson Historic pots. They are not a special value! I have measured them from 425 to 525K. They are very nicely made better than any other cts pots I have tried recently. But they are not selected for a specific value. I think the difference between the two is one says it is ROHS compliant, it cost more too. They did change the description of the 530K pot to say 500K. They told me 530K is the gibson part number.
Get the R-V530-GIB it is $1 less and not ROHS .
I have never tried the R-V510-GIB, I think they told me it has Gibson embossed on it too. If it does it might be one of the crappy gibson pots.

I hope this clear up this mess, sorry if I caused any confusion.

[rooster]

OK, thanks, billyZ, I get it the part thing.

paulster, OK, I see your point. What confuses me here is what I was told is the constuction of the carbon. I was told via an article in Premier Guitar, I believe by R.G.Keen, that a pot actually has two different carbon traces. And they are joined by a rather long splice that is at an angle that travels almost 5/8ths of the trace. So the wiper starts entirely on the first trace that is of a low resistive value, and as it continues along it's path (which is getting narrower) , the wiper starts to hit the other trace (at an angle) which is a higher value. For a time, the wiper is riding on both traces, but then it is all the second trace. Naturally, the second trace (the one towards the back of the pot) is of a much higher value.

So, you may be right, but I have never seen or heard of a trace that is 4 parts. I will look around and find the article, maybe post a pic. When it was explained this way, using the 2 parts, it made perfect sense and still does. Too, the wiper itself has typically 2 brushes, one on the inside of the trace, one on the outside, which, again, seems logical since you are combining two different traces.

[rooster]

Alright, not an easy thing to do, copy pics. I did not find the article I read but the Premier Mag site did have something by somebody, Dirt Wacker. billyZ you are right, I did not 'get' the idea of the smaller trace having more resistance.

Here is his info, info that relates to what you are talking about. (AND, BTW, all of this pertains to Audio Taper pots, of course.) It seems that in cheaper pots - and I am not clear that this would include the CTS, Centralab, or PEC pots - there does seem to be the use of a strip that tapers from one end to the other. Now, I suppose this taper could be minimal in width or even thickness but they don't say. And it would do this:

"If you widened the carbon strip overall then it would provide less resistance, meaning more current would flow through it, just as more current can flow through a large wire than through a small wire. Similarly, if you narrowed the carbon strip, then resistance would be increased and less current would flow. But what if you tapered the strip, making it wide at one end and narrow at the other? As you might expect, a tapered strip would provide more resistance at one end than at the other, as shown in the following illustration."

Well, no illustration, sorry. But this explains your idea about scraping the width of the trace, and I understand the results now.

I guess the question remains for me whether or not I see this type thing on the pots I am using, this trace getting smaller at one end. It could be a thickness thing and I wouldn't notice that, I suppose.

Well, OK, point taken then. And I have to assume that this scraping would work on pots with quality traces, too. ?? Sure, why not? It also becomes clear to me that if you are going to increase the pot value, you had better do it at the 'back' end, or narrower end of the trace.

BTW, are we in agreement on this?

[vibratoking]

Here is the mathematical definition of resistance:
R=pL/A

p = is the electrical resistivity of the material
R = is the resistance total resistance
A = is the cross-sectional area of the conductor
l = is the length of the conductor

p is a property of the material and is fixed for a particular pot. L is also fixed for a particular pot. A is what is being changed by scraping or sanding or whatever method is chosen.

Notice this has nothing to do with how well the surface is polished. Although, that does come into play as a second order effect.

Two things can be accomplished by scraping. The first is to increase the total end to end resistance. The second is to change the linearity of the sweep. The second is the property that concerns me the most. Careful scraping can change both for the better.

[paulster]

Two things can be accomplished by scraping. The first is to increase the total end to end resistance. The second is to change the linearity of the sweep. The second is the property that concerns me the most. Careful scraping can change both for the better.

Absolutely. Done carefully you could get a higher reading, which is good as most 500K pots read well under but also a much better taper.

Win, win. So long as you're very careful with the exacto knife!