PlayJazzGuitar.com Forum

[chordspinner]

Hey, Guys. I need some help here. I have a circa 1980 Gibson Howard Roberts Fusion guitar and the pots are just worn out and need to be replaced. There are no guitar shops close and I use the guitar all the time so I thought I'd change them out myself. Can anyone direct me to a site where I can find out what resistance to get and what shaft size. I find 300kohm and 500kohm, long and short shaft and audio and linear taper. (I'm pretty sure the originals are audio taper, aren't they?) I want to stay with original type on guitar unless there's a big improvement. I've done quite a bit of electrical wiring/soldering etc. so I think I can handle it. It looks like a big task working through the f-holes not to scratch anything.
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Chordspinner

"You're either at the gig or waiting to go to the gig."

[Gorecki]

From the sounds of it you shouldn't have any trouble with swapping them out. They 'should be' 500k pots all the way through and I would suggest replace any cap's as well. I use Stewart McDonald http://www.stewmac.com for most of my supplies but you should be able to get the pots from many places if not Radio Shack or the like.

Now be prepaired for the possibility of it changing the sound of the guitar in some way. An electric guitar is a collective of it's parts and even pots can have minor differences in resistance causing a change in sound.

[chordspinner]

Thanks, Gorecki. That's one of the things I was worried about. One manufacturer of pots claimed that other (cheaper, of course) makes could vary in their claim of 300k or 500k by as much as 45%....and his was only 5%. I suppose that's what you mean about the sound being altered. Do you know which is which on audio or linear taper and which shaft length? If I got the "Gibson" brand perhaps that would be closest to the original?
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Chordspinner

"You're either at the gig or waiting to go to the gig."

[chordspinner]

Gorecki: Also, thanks for the website. I couldn't get connected to it yesterday but it worked today. The 500 vs 300k question was answered: the 500k's are generally used for humbuckers; the 300k's, for single coil. They said also, if you want to hear your guitar "wide open" to try the one meg pot.
Another question, this time about a strat. I have a Fender Strat with "Fender Lace Sensor" single-coil pickups on it. I'm trying to use it in a stage show and it simply isn't working. The noise (high amount of hiss and noise) coming from the guitar is the problem. I worked endlessly with the sound man last night trying to isolate the problem and it just has to be the guitar. I'm wondering if there's a wiring problem or this is idiosyncratic of the guitar? I just love the guitar and the show requires this kind of sound. Again, no luthier withing a 100 miles!
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Chordspinner

"You're either at the gig or waiting to go to the gig."

[Gorecki]

[chordspinner]

You're right, I did a little research on the pickups and they're supposed to be "high output, low-noise" by design. I've had the guitar about three years (bought from a friend-it was made in 1992) and had noticed it being a little noisy but it was in a room with bad ground and lots of electrical interference but I never really had the chance to trouble shoot it like last night. It happens on all pickups, or two together. I took it apart and checked all the solder connections. They all look good including the ground. My multi-meter is really basic; I don't think I could get it to the gnat's ass. It has a tremolo stabilizer in it. Could that interfere with the grounding? It shouldn't. If the main volume pot was bad, how would it act?
Thanks again for your help. Your questions really made me think.
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Chordspinner

"You're either at the gig or waiting to go to the gig."

[Gorecki]

If a pot's bad it will usually, not work at all (prevent sound, or do nothing when turned, or short out) with the exception of being wornout/dirty where it will make a scratching sound when turned.

The only way I could think a trem stablizer (tremsetter, hipshot, treml-no) could cause it is if somehow by chance a ground loop was created by it touching (making continuity) between two points it shouldn't. The trem (it's springs, screws..etc) is part of your ground and if it caused a loop you could find out by testing continuity between the top of your bridge (or even a string) and the trem setter. If you get continuity it's certainly touching ground and finding where it shouldn't touch (if it is) will be trial and error.

Is there any shielding inside the guitar cavities? Silverish, copperish, or black tarish sort of paint? If the ground and the shielding get looped (the stablizer could be causing it) that'll make some noticable noise.

The worst case is to trouble shoot each component. The simplest way (not quite simple but) is to disconnect everything between a pickup and the output jack, wiring directly to the jack, test it and move to the next to find some answers to variables.

Just as a gentle reminder, strat's are well known for being noisy (the single coils thing again) and often aren't shielded enough.

Here's some resources to help out.

http://www.guitarnuts.com/wiring/index.php

[cmr415]

While single coils generally use 250k, Most jazz style humbuckers use 250k pots for the tone.
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[Gorecki]