Eliminate Presence control ?
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Eliminate Presence control ?
If I wanted to eliminate the presence control on an Express and set the negative feedback somewhere near the middle of the 4.7k pots sweep what value resistor would I run to the top of the 10k-.1uf junction? Most amps with no presence control are around 820r but the 100k that is already in place has me wondering. . Thanks : JOE
Resistors not Transistors !
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skyboltone
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Re: Eliminate Presence control ?
Well Joe the 4.7K pot has me guessing. I'm finding mostly 5K. This is what I think you mean. If you want to make a preset presence control on an express, replacing the pot with a 1.2K resistor equals about 9:30 on the chicken head knob. If you want half the presence you'll have to twist the knob to the amount of presence you like then measure between the wiper and the ungrounded outside leg of the pot. Substitute a fixed resistor.joe6v6 wrote:If I wanted to eliminate the presence control on an Express and set the negative feedback somewhere near the middle of the 4.7k pots sweep what value resistor would I run to the top of the 10k-.1uf junction? Most amps with no presence control are around 820r but the 100k that is already in place has me wondering. . Thanks : JOE
I've been doing that the last couple of builds because I have been experimenting with another circuit in that knob spot. Seems to work.
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Eliminate Presence control ?
Thanks , I was looking at the Ceaira tone layout when I posted the question & it shows 4k7 but yea I probably have a 5k in there. I was wondering the same thing, if this is somthing where I can just take a measuerment & plug in a resistor? (with that value) & as you guessed I want to use that hole for something else - a master vol of some sort. .. Thanks : JOE
Resistors not Transistors !
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skyboltone
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- Joined: Wed May 10, 2006 7:02 pm
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Re: Eliminate Presence control ?
That's the ticket, just put it where you like it, measure the pot and sub in a fixed resistor. All the Fenders that had NFB and no presence control were done that way.joe6v6 wrote:Thanks , I was looking at the Ceaira tone layout when I posted the question & it shows 4k7 but yea I probably have a 5k in there. I was wondering the same thing, if this is somthing where I can just take a measuerment & plug in a resistor? (with that value) & as you guessed I want to use that hole for something else - a master vol of some sort. .. Thanks : JOE
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.