No-load tone pots & treble-bleed vol on MIJ strat

Discussion in 'Tech-Talk' started by shunter, Jan 25, 2020.

  1. Believer7713

    Believer7713 The Pink Bunnyman Frankenstein Silver Member

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    All of my guitars that I've put linear pots into are a smooth taper all the way through the sweep. Those with logarithmic pots have an almost on off effect from 6/7 to 10. It sounds to me like your linear pot is messed up or is actually a reverse logarithmic taper. Either way it sounds like you need it changed. The taper of a logarithmic pot is what makes it great for pinky swells because 80% of the control is after 6 on the knob. Try doing the same pinky swell on a linear pot and you have to roll the knob down to 2. Plus the logarithmic pot is what the ear actually perceives like a dopler effect. It's nearly impossible.

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  2. shunter

    shunter Strat-Talker

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    you’re talking about volume I think? My volume seems to have a smith roll off but my tone does not-much, then it does everything
     
  3. AngeloEvs

    AngeloEvs Strat-Talker

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    I would check to see exactly what type of potentiometers are currently fitted for tone. The standard marking most used to differentiate between log and Lin is the prefix A or B followed by the resistance I.e. A250k = Log (audio) taper.

    If they are log and you are getting the 'on' or 'off' effect then the potentiometers may be worn or the carbon track intermittent in which case they would need cleaning with switch cleaner or replacing if that fails. Potentiometers can be tested but you would need a multimeter in order to check their function.

    I have just replaced a volume potentiometer that exhibited the 'on' then suddenly 'off' - it was a case of just being worn out.
     
  4. shunter

    shunter Strat-Talker

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    Oh thanks. I was wondering if I can tell from just looking.
     
  5. Guitarmageddon

    Guitarmageddon Dr. Stratster

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    Fender Japan Strats of the time ALWAYS ALWAYS used A250 Alpha pots.....
     
  6. Believer7713

    Believer7713 The Pink Bunnyman Frankenstein Silver Member

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    A potentiometer will work the same whether it is a volume pot or a tone pot. The difference is the lpf cap. If you have a single spot that works like a switch, whether it be a log (A) taper or linear (B) taper then you may have a bad, or dirty, pot. A lot of people like to use the B tapers for the tone positions because they are linear...meaning that on a graph as shown earlier if you turn your knob to 1 on the x axis, inversely your tone changes equally on yhe Y axis. This actually makes the tone easier to dial in and find a spot to set it for a song and is more consistent from rig to rig. What you're describing sounds like either an A taper or a bad pot. An A taper starts out with very little then as you turn it up it gets exponentially louder as you roll it on. It simulate the decay of sound waves and proximity to them as we hear them at different volumes, or tones as the case may be.

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  7. JohnDH

    JohnDH Senior Stratmaster

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    Just to clean up a few points on pots:

    Tone pots

    Most tone pots are log, and most people will prefer that. Most of the audible tone change is in the first few k as you increase treble, and log pot spreads that out over the first half of the turn. To get the last tad of treble needs the rest of the resistance like 90% of it. I think a really good option if you want a wide control, is a no-load tone pot. You can use a lower value like 250k instead of 500k for a smooth range, with an extra bit of treble as you arrive at no-load at 10.

    Volume pots

    Most are log. I find that they result in a very quick apparent volume reduction as to turn down from 10, too fast for me. Good for quickly cleaning up distorted tone, but not sensitive enough to reliably find a small volums reduction in a clean tone.

    Linear pots are much slower to reduce volume. They can also be good in two volume guitars like LP's if you want to set a particular mix, where relative volumes are very critical.

    Volume with treble bleed

    There's a sweet spot IMO, using a log volume pot with a correctly sized resistor-capacitor in parallel as a treble bleed. Not only is this the best of all simple designs for controlling treble loss, but at the same time, it also reduces the sharpness of taper on a log pot. It becomes halfway to linear, about 30% at mid turn. I find this to be ideal and so I have it on all my guitars.

    But, it's all a matter of opinion, so have a go. I think it helps to have some insight into what to expect when making the choices.
     
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