1.2M resistor in parallel with 500k audio volume pot????

[Mr Clean]

I'm trying to get to a 350k pot. Using the subject values gets me where I need to be resistance wise, but puts most of the taper in the bottom third of the pot. Half turn measures 300k. Haven't put it in to test because I've never heard anyone using a resistor size larger than the pot.

Trying to use stuff I already have but wondering if maybe using 500k linear might be better. But once I go linear than all I would need to do is go with a 300k linear on the fat side of the tolerance. I would like to stay with audio taper if possible....

 

[DrNewcenstein]

Re: 1.2M resistor in parallel with 500k audio volume pot????

Where are you connecting the resistor? Casing and which prong? Try each one and see what's what.

I'd assume that using a resistor larger than the pot's value will result in a faster and more drastic result, though, so maybe instead of a 1.2Meg resistor, you could go above the pot's value by the amount you wish to decrease it? 750K-800K resistor might drop it down in a more manageable ratio.

Then again, re-reading the post, you've already got the 1.2Meg on it? If that's the case, then you might want to look at going with a 150K resistor on the center lug. That should cut the max down to 350K.


Another thing you can do as a test is to wire that pot to another pot, and see what readings you get at various settings of pot #2 (which is just a variable resistor). Find what works for you that way, then match resistors to that value.

 

[Mr Clean]

Re: 1.2M resistor in parallel with 500k audio volume pot????

Right now I have the 1.2m resistor on the two outside lugs, and nothing is soldered up yet. I've got a 150k resistor so I will see how that measures. But when you say center lug does the other end go to ground or input?

Thanks for the reply!!!

 

[DrNewcenstein]

Re: 1.2M resistor in parallel with 500k audio volume pot????

I'd go to ground with it, but try it both ways - you never know which you'll like better tonally. If you're just going by the meter readings, go to ground.

 

[njstoehr]

Re: 1.2M resistor in parallel with 500k audio volume pot????

Ohms law in action!

Resistors in Parallel add up like this: 1/R1 + 1/R2 = 1/R3 So if you want a Value of R3=350 (or the final value of the Pot) than 1.2M will get you really close (something like 353k). YOu will want to solder the 1.2M across the two outside lugs of the pot.

Pros: You can easily change the overall value of the pot quickly, and it is reversible. You also get to hear what a given value pot will do to your overall tone.
Cons: Changes the taper to act more like a linear taper.