Gibson Historic potentiometer....

[Littlewyan]

Ah I see, that makes sense. Thanks

[bcmatt]

I bought a quad Gibson Historic Pots from AES and they really made a huge difference in the control of my Express and Liverpool with the 57 classic HBs in my SG. I was very impressed.I also tried a number of different type and value of tone caps to get something I liked best.

Anyways, I don't know if this is a mistake or something, but our big Canadian Music Store, "Long & McQuade" seems to have the historic pots even cheaper than their other typicial Gibson pots... the cheapest I've seen yet not even considering this is also Canadian Dollars which is also quite low right now:
https://www.long-mcquade.com/51816/Guit ... _Taper.htm

[Mark]

Did you measure the values of the pots at all. If so what were they?

[rooster]

Mark, here's a measurement from two I have in blister packs, unused as of yet: 513K, 477K.

[Mark]

As previously discussed here are some photos of the whole process.

I decided to sacrifice the pot I have to see what can be done to improve the resistance value. My reasoning was this isn't TGP, so surely some level of DIY is expected and pots are cheap (mostly).

As far as sand paper goes I decided to use crocus cloth. I used it as it is extremely fine and would be forgiving to the pot during my hamfisted efforts.

http://en.wikipedia.org/wiki/Crocus_cloth

This is the crocus cloth I used and it shows the carbon removed from the pot.
[img766]http://i149.photobucket.com/albums/s69/ ... 9c66a4.jpg[/img]

The parts in the pot.
[img766]http://i149.photobucket.com/albums/s69/ ... a27993.jpg[/img]

The original values of the pot.
[img:766:1024]http://i149.photobucket.com/albums/s69/ ... 45c7cc.jpg[/img]

The mid point on the pot.
[img:766:1024]http://i149.photobucket.com/albums/s69/ ... f2cf7c.jpg[/img]

After the sanding and putting the pot back together.
[img766]http://i149.photobucket.com/albums/s69/ ... bab3d1.jpg[/img]

The mid point of the pot after the sanding.
[img766]http://i149.photobucket.com/albums/s69/ ... f9ce7e.jpg[/img]

I couldn't get the circlip (ring) back on the pot properly, as far as I could tell it is there to stop someone pushing the back off the pot via the control knob.

I've only taken one measurement, but it would appear that the taper hasn't been effected by my sanding, though I've only measured at one point.

A big thank you to all of Roosters assistance on this one.

[Littlewyan]

Excellent. Thanks for doing this Mark. I did wonder how the taper would be effected but seeing as the midway point is still at 10% I'd say its pretty much the same in this instance. I imagine you have to be careful with sanding off the same amount and not more on one side than the other. Did you give it a quick swipe or were you careful with sanding the pot at the same speed and pressure all the way across?

[Mark]

I tried to do a single even wipe at a time. Realistically speaking I can't be sure that even pressure was applied or what pressured was applied.

When using crocus paper it took about 5 to 8 wipes to get the resistance at 499K. However I'd rather take more gentle wipes than one wipe where the pot would be rendered useless in a single wipe.

I think given it is a random process, concerning pressure applied to the pot to remove carbon and the fact I don't know how the manufacturers get a particular taper on the resistive element. I can't truely be sure of the results of removing carbon from pot to pot.

Rooster technique is based on how the pots are made, CTS spray the carbon on to the base and the resistance is determined on how much carbon is on the base.

[rooster]

You got it Mark, nice job. Crocus cloth is super light for the task at hand but only because it will clog faster. But if you keep selecting a new section of 'cloth' then you will remove some carbon. And of course you can measure your work at any time, anywhere on the trace.

As to the metal ringlet (C-clip), I see this as an assembly helper for the manufacturer. If you think about it, putting the ring on the shaft allows the pot building process to be passed on to another assembly station, machine or human I have no idea. That's my thought anyway, and I don't replace it. Also, FWIW, I actually remove the mass of sticky factory grease in the base and substitute a small amount of lithium grease. I also remove some of the molded 'ring' (height) within the plastic base to reduce the pressure of the wiper on the trace. It's about 1/16" tall stock, I circular sand it on 600 grit to 1/32" or so. Sometimes I will even collapse the wiper collar to reduce this pressure; and more, I even circular sand the pot shaft so that the lines on the shaft are horizontal and not vertical. All in hopes of reducing friction so that the pot is easier to move. Well, if that's a goal for you.

[bcmatt]

In my crazy SG type guitar with 57 Classics in it, my historic pots that I installed measured:

525K, 531K, 531K, and 535K? (the last one got rubbed off but it was the highest)

I bought a 2014 Melody Maker Les Paul yesterday because a miss me some P90 tones. Luckily I got this deal on these Historic pots and already have a set ready to go in. They measure:
511k, 525k, 532k, 539k

I didn't realize that I have to yank out a PCB get these in!

Anyone have experience using these pots with P90s? I'm guessing it will still pay off to do the 50s wiring, etc...[/code]

[Reeltarded]

Yeah with 500k on P-90. It acts like reduced mids because the highs extend.

I detest these historic pots. I like the taper but I have yet to see the numbers you guys are seeing. 470 range.. usually.

I like 500k Alphas. Great action and taper. 10 is 10+.

[bcmatt]

But, all modern Gibsons come with some sort of 500K pot don't they? My MM I just got says it has non-liner 500k Pots... I'm assuming I'm just changing the taper by putting in the Historics.

Of course, I would put in the lowest value in the Bridge volume though...

[rooster]

bcmatt, your readings are unusual from my experience. What kind/brand of meter are you using? Reeltarded's experience is way more typical than yours. That said, I would not be using the Alpha pot because I think their build quality is not up to CTS. I see that they even make wah wah pots these days.... I can't imagine using them for a wah that I was going to actually use. Eh, kinda an Alpha disliker.

[bcmatt]

Mine aren't normal? Am I the only one getting numbers above 500k?
It's on all 8 of mine...
I use a Klein MM1000 Digital Multimeter.

I bought some pots for a friend's guitar so I will measure those 4 soon too...

I wired mine into my Melody Maker last night after I got the PCB out. I really should have routed new wires to the pickup selector because these ones are making this look a little hokey of a hack job after the conversion... much more useable controls now though.

[telentubes]

The four I bought measure 490, 510, 530, and 540.

[rooster]

Wow, I love seeing these high numbers. My experience has not been the same but maybe my supplier is dealing with older stock or something. CEDist, BTW. These are all Taiwan so maybe our Asian brothers/sisters have at last tasted the vintage Gibson kool-aid. It would be nice to think the majority of these 'historic' pots are at least hitting 500K. Thanks for the measurements.