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previous: Dick Hi all,I was wondering if you c... -- 9/15/2002 1:13 PM

Re: Different volumes?

9/15/2002 1:39 PM
Mark Hammer	Re: Different volumes? This is probably more a question for the guitar sub-forum, but what the heck. 1) Make sure the heights of the pickups are properly adjusted since that can make a big difference in their tone and output level. If a cover was recently put on one then I am assuming it was removed from it's location on the guitar, worked on, then re-installed and the height-setting screws tinkered with. 2) Removing the tone cap will mean less bleed-off of high end than having the cap bleeding high end through an always-on 500k tone pot, but the difference in overall volume level because of that is negligible, unless there was something seriously wrong with the way it was done (i.e., something shorting out) or there was something seriously wrong with your previous wiring. You've given no indication of anything wacky going on with the wiring, but you HAVE indicated that the height of the pickups (relative to each other) may have been altered, so my first inclination is to look at the distance of the pickups from the strings and determine which of the two is set either higher or lower than it ought to be. You can easily adjust this, and keep a record of the polepiece top to string distance for future reference. Assuming that the level difference IS more or less set by virtue of replacing the cover (though I doubt it would make that much of a difference), what can you do to make it so that the two pickups provide roughly equivalent output levels for each nominal setting of their volume controls (i.e., same volume at "7")? There is nothing magical about pots as resistors. All they do is provide a way of simulating two resistors in series with a tap at their junction. There is nothing magical about 250k or 500k. All they provide are standard values intended to capture most of customer's needs so nobody busies themselves with making 275k pots, 340k pots, etc. The total load provided by the pot can be easily added to or taken away from by reasonable amounts without disturbing the tone of the pickup (i.e., the tone produced by the load imposed on the next stage in the signal chain, including the patch cord to get there). If you stick a resistance in series with the input to a pot, the pot behaves as if it was the total value of its' own resistance plus that extra amount, but turned down a bit. So, a 500k pot with a 47k resistor on its input behaves like a 547k pot (and they will usually be lower than 500k even though they are labelled as such), turned down about 10%. This should not impact the taper of the pot all that drastically, if at all. While you're in there, you might want to check whether the two pots are both log taper. If you replace one with a linear taper that might explain why getting a balance is difficult at the same nominal setting. So, to sum up: - verify same pot taper type - verify the height settings of the pickups - install "balancing" resistor if necessary

9/15/2002 1:39 PM

Mark Hammer

Re: Different volumes?

This is probably more a question for the guitar sub-forum, but what the heck.

1) Make sure the heights of the pickups are properly adjusted since that can make a big difference in their tone and output level. If a cover was recently put on one then I am assuming it was removed from it's location on the guitar, worked on, then re-installed and the height-setting screws tinkered with.

2) Removing the tone cap will mean less bleed-off of high end than having the cap bleeding high end through an always-on 500k tone pot, but the difference in overall volume level because of that is negligible, unless there was something seriously wrong with the way it was done (i.e., something shorting out) or there was something seriously wrong with your previous wiring.

You've given no indication of anything wacky going on with the wiring, but you HAVE indicated that the height of the pickups (relative to each other) may have been altered, so my first inclination is to look at the distance of the pickups from the strings and determine which of the two is set either higher or lower than it ought to be. You can easily adjust this, and keep a record of the polepiece top to string distance for future reference.

Assuming that the level difference IS more or less set by virtue of replacing the cover (though I doubt it would make that much of a difference), what can you do to make it so that the two pickups provide roughly equivalent output levels for each *nominal* setting of their volume controls (i.e., same volume at "7")?

There is nothing magical about pots as resistors. All they do is provide a way of simulating two resistors in series with a tap at their junction. There is nothing magical about 250k or 500k. All they provide are standard values intended to capture most of customer's needs so nobody busies themselves with making 275k pots, 340k pots, etc. The total load provided by the pot can be easily added to or taken away from by reasonable amounts without disturbing the tone of the pickup (i.e., the tone produced by the load imposed on the next stage in the signal chain, including the patch cord to get there).

If you stick a resistance in series with the input to a pot, the pot behaves as if it was the total value of its' own resistance plus that extra amount, but turned down a bit. So, a 500k pot with a 47k resistor on its input behaves like a 547k pot (and they will usually be lower than 500k even though they are labelled as such), turned down about 10%. This should not impact the taper of the pot all that drastically, if at all.

While you're in there, you might want to check whether the two pots are both log taper. If you replace one with a linear taper that might explain why getting a balance is difficult at the same nominal setting.

So, to sum up:
- verify same pot taper type
- verify the height settings of the pickups
- install "balancing" resistor if necessary

Replies:

Dick Thanks Mark; I greatly appreciate i... -- 9/16/2002 1:46 AM