Increasing a Tone Pot Value for Just One Pickup?

[JackFawkes]

I tried searching for an answer before starting this thread, please forgive me if I use any incorrect terminology (which could possibly explain why I couldn't find an answer to begin with).

If I have a strat-style guitar with a common 5-way switch and the following pots: 
250K Volume (global)
250K Tone (neck) 
250K Tone (middle/bridge) 
That means there's a wire between B1 and B2 on the switch, like the red line in this diagram: 


But what if I wanted just the bridge pickup to be a little brighter while still having the ability to do a little treble-cut?
1. Could I replace the wire between B1 and B2 with a 250K resistor? 
2. Would that raise the resonant peak of just the bridge pickup a bit, without affecting the middle pickup in switch positions two or three? 
3. Would there be any other side-effects other than the bridge pickup's Tone pot "range" now being 500K-250K (instead of 250K-0K)? 

Thank you all for sharing your knowledge and time! 

Jack 

[Yogi B]

Jun 16, 2022 15:28:11 GMT -5 JackFawkes said:

But what if I wanted just the bridge pickup to be a little brighter while still having the ability to do a little treble-cut?

How little "little" is worth it?

1. Could I replace the wire between B1 and B2 with a 250K resistor?

You could, but I wouldn't expect it to be all that useful.

2. Would that raise the resonant peak of just the bridge pickup a bit, without affecting the middle pickup in switch positions two or three?

Yes, though the resonant peak would not change by much. And, to be absolutely clear, this also wouldn't affect the bridge pickup in position two either — only doing anything in position one.

3. Would there be any other side-effects other than the bridge pickup's Tone pot "range" now being 500K-250K (instead of 250K-0K)?

None.

So, overall whilst it does technically fulfil your wants, it comes back to my opening question.

The trouble is: the range of 500k—250k likely won't result in that much of an audible change — remember that this is also in parallel with the volume control which adds loading too. Therefore the range is actually more like 167k—125k (versus the original 125k—0k), so (at maximum) a reduction in loading of only one quarter rather than one half. (Slightly lower still, if considering the input impedance of what you're plugged into & the pickup's intrinsic damping.) Realistically I'd expect the increase in the resonant peak to be a couple of decibels at most, and with this change being spread across the entire range of the tone pot (though most of it happening from 10 down to 5), I doubt it would sound like the pot was doing much, if anything.

I'd also argue that it takes a somewhat generous reading of "still having the ability to do a little treble-cut" in order for this to qualify. Whilst true that there would be some slight treble-cut, the new version's minimum treble setting would be identical to the current maximum — so relative to that current maximum you wouldn't "still" have treble-cut.

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If I were doing this I'd probably use a modded dual gang pot: keeping a 250k gang for the middle tone control; using a secondary 1Meg (log-taper) gang (possibly also modded to be no-load at 10) in series with, say, a 51k resistor — in place of the red jumper / your suggested 250k resistor. In comparison to the original wiring: at maximum the increase in resonant peak would be closer to 3dB, and as large as you could hope for without also messing with the volume pot; the minimum setting, governed by the 51k resistor, is equal to the current 250k pot set to about "7"; overall giving a wider range than the suggested resistor version and better spreading that range over the rotational sweep, but at admittedly higher complexity.

[JackFawkes]

Thank you for all that insight! 
Yeah, a dual-ganged pot would be a pretty great solution... hmm...