need advise on pots and caps.

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by gleno, Jan 25, 2006.


  1. gleno

    gleno Guest

    I recently installed a set of Fralin Vintage Hot pups in a US Strat..It has 250K pots and caps with a value of .333, THe sound is too dark, what happens if I go to 500K pots or even the 1meg pot? What happens to tone? The same with the caps..What should they be? THanks
     
  2. Jim Collins

    Jim Collins Member

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    First, you ought to test the value of the pots. Just because they say 250K doesn't mean they really are. I recently replaced all four pots in my two Teles. Each of the old pots measured 220K, whereas they each said 250K. The new pots each measured 250K, or slightly above. The difference, in sound, was quite noticeable. (Actually, I replaced them not because they measured low, but because they were getting noisy. It wasn't until I took them out that I measured the old ones.)

    You could try .022uF tone caps, or even a .01uF.

    If you were to replace the pots with 500K, the tone would be significantly brighter when the volume is full on. (Personally, I would describe this as "strident" rather than "bright", but those are my ears, not yours.) You would notice a rather dramatic loss of highs as soon as you backed off on the volume, just a little. Were you to go with 500K pots, you'd probably find you need a treble bypass cap. Were you to go with a 1Meg volume pot, the shrillness at full volume, and the loss of highs as you back off on the volume, would get even more noticeable.

    Does this guitar have no-load tone pots? If it doesn't, you might think of replacing the current tone pots with no-load pots. (Don't do this for the volume pot.) When turned full on, the no-load tone pot removes the tone control from the circuit. If that isn't bright enough, then you might need brighter pickups.
     
  3. gleno

    gleno Guest

    THanks Jim for the reply..This guitar has a tonecontrol that from 0-5 acts like a normal tone control, and from 5-10 it gets a really full, muddy kinda tone..Not really knowlegable about this type tone control..Are you?
     
  4. stratofied

    stratofied Member

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    I agree with Jim, there is a wide tolerance on pots so you should test them. I use 300k pots on one of my strats with WCR PU's. The taper feels a little different but it will brighten things up a bit. I fact I'm thinking of going back to 250k so I can't see 500k working very well at all, for me anyway.
     
  5. Jim Collins

    Jim Collins Member

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    The tone control you describe sounds like a TBX control. I prefer a regular tone control over a TBX. I think you might like no-load tone controls, in both positions.

    There is something else you might consider, especially if you like to use the two, inbetween positions (neck+mid and mid+bridge). Your guitar is probably set up so that both tone controls affect the neck+mid position. This is not optimal, and can contribute to muddiness. There are a few ways you can deal with this. One is to arrange your tone controls so that one affects the neck pickup, and the other affects the bridge pickup. The middle pickup would have no tone control. (The Jimmy Vaughan and Eric Johnson Strats come this way.) In either inbetween position, you have only one tone control affecting the sound. The drawback is that you have no tone control on the middle-only sound. If you feel you need that, too, you could replace the switch with a Super Strat switch (4P5T), which would allow you to still have two tone controls, while giving each position only one tone control.
     

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