Author Topic: reducing the effect range of a pot question...  (Read 1213 times)

B_of_H

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reducing the effect range of a pot question...
« on: January 12, 2011, 02:49:10 PM »
So I have two circuits that i'd like to reduce the effective range of the pot on.

one is a tube screamer like circuit and i'd like to make the drive control go from 1 to 3 only rather than 1 to 10 (as in 10 = max gain).   Is it as easy as raising the value of the 51k off the drive control?

can I just put a resistor in between two lugs of a pot or in series with one lug? 

Say lug 3 is to GND on a 500k pot and I want only 250k to 500k worth of range: what do I do?

stecykmi

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Re: reducing the effect range of a pot question...
« Reply #1 on: January 14, 2011, 02:10:37 PM »
Say lug 3 is to GND on a 500k pot and I want only 250k to 500k worth of range: what do I do?

put a resistor in series with lug 3 to ground. this will make sure that there is never zero resistance between lug 2 and ground and therefore there will always be voltage there (since ground is 0 V). Without doing the math, intuitively i think it'll be 250k resistor to get a the sort of divider you're looking for (that's unverified, I can try and work it out later if you need).


So I have two circuits that i'd like to reduce the effective range of the pot on.

one is a tube screamer like circuit and i'd like to make the drive control go from 1 to 3 only rather than 1 to 10 (as in 10 = max gain).   Is it as easy as raising the value of the 51k off the drive control?

Since the drive control is in a feedback loop, and MORE resistance in a loop INCREASES the output, you need to remove some resistance. I don't have time to do the math right now, but I think you should get a pot that's about 1/3 the resistance of the current one.
« Last Edit: January 14, 2011, 04:40:56 PM by stecykmi »

B_of_H

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Re: reducing the effect range of a pot question...
« Reply #2 on: January 14, 2011, 06:18:30 PM »
thanks, yeah I did some tinkering yesterday and played with different ideas.  I appreciate the input.