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PostPosted: Wed Sep 05, 2018 11:09 am 
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Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
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Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
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I have a customer with an Ibanez guitar that has 3 super tiny individual cavities for the two pots (volume and tone) and switch. It's a really annoying design. Anyway for his own reasons he wants to replace the tone knob with a simple 2 way switch that is tone on tone off, have any of you seen such a thing? Would an appropriate capacitor attached to one of the positions on a two way switch work without the pot attached?


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PostPosted: Wed Sep 05, 2018 11:18 am 
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Koa
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Joined: Fri Aug 19, 2005 4:02 am
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Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
I recently rebuilt an old Gretsch that had a 3-way switch connected up with capacitors to provide three tone settings. You can google "Gretsch tone control circuit" to see a diagram.



These users thanked the author Barry Daniels for the post: Conor_Searl (Thu Sep 06, 2018 11:18 am)
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PostPosted: Wed Sep 05, 2018 12:16 pm 
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Koa
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Joined: Thu Nov 04, 2010 1:46 pm
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First name: Freeman
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Conor, if you understand how the tone circuit works you'll know that the capacitor selects which frequencies (the trebles) are passed to ground, the pot selects how much is passed. There are a number of ways to wire them but this is typical

Image

You can see that when the pot is turned all the way up there is the full value of resistance (250K, 500K) in series with the cap, that essentially turns the cap off. When it is turned to the full down position all of the signal goes to the cap, thus all of the trebles are attenuated. If you want to duplicate that put a 250 or 500K resistor in series with the cap and put your switch so it shorts out the resistor. You could also leave the fixed resistor out but wouldn't quite duplicate the circuit that you currently have. You could also put in fixed resistors of different values to duplicate partial pot positions (but remember the pot is probably log taper so you'll have to actually measure its resistance at the position you want.

Obviously this would be very easy to test on your bench with a couple of alligator clips and a fixed resistor from Radio Shack.



These users thanked the author Freeman for the post: Conor_Searl (Thu Sep 06, 2018 11:18 am)
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PostPosted: Thu Sep 06, 2018 11:20 am 
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Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
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Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Barry Daniels wrote:
I recently rebuilt an old Gretsch that had a 3-way switch connected up with capacitors to provide three tone settings. You can google "Gretsch tone control circuit" to see a diagram.


Barry, that looks like the ticket. Thanks. My customer wants to swap his volume and tone knob because his hand always hits the volume knob where it is and he thinks a small switch may be less obstrusive than the pot. He doesn't really use his tone knob much anyway. I gotta say though, accidentally bumping that "mud" switch would be way more of a downer than bumping the volume knob.


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PostPosted: Sun Sep 09, 2018 2:50 pm 
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Koa
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Joined: Fri Aug 19, 2005 4:02 am
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Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
By the way, TV Jones sells a replacement wiring harness for this setup that is really well made. I don't know if it would work for your guitar without modifications, but it sure did save me a bunch of time on that Gretsch restoration.



These users thanked the author Barry Daniels for the post: Conor_Searl (Sun Sep 09, 2018 6:25 pm)
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PostPosted: Sun Sep 09, 2018 6:29 pm 
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Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
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Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Barry Daniels wrote:
By the way, TV Jones sells a replacement wiring harness for this setup that is really well made. I don't know if it would work for your guitar without modifications, but it sure did save me a bunch of time on that Gretsch restoration.


Thanks for the tip Barry. This is a super thin, heavy metal, strat style guitar, it would be easy enough to do the wiring, just finding parts that will fit the cavities is the trick. I already went through it once with him trying to replace the old worn out 5 way switch. But I'll keep that in mind for any hollow guitars that come along. The customer's decided to trade the guitar for an epiphone les paul so I can stand down my problem solving.


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PostPosted: Fri Sep 14, 2018 5:13 pm 
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Koa
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We have a customer that has all of his 'metal' guitars as master volume only guitars...they get a fixed value resistor and cap wired in series to ground plus the usual treble bleed...done to reduce the 'ice pick in ear' effect of his current Fishmans. This is essentially what would happen if the tone pot was replaced with a simple resistor of the same value as the current setting.

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These users thanked the author Woodie G for the post: Conor_Searl (Sun Sep 16, 2018 5:46 pm)
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