madbeanpedals::forum

Projects => General Questions => Topic started by: MarkL on April 17, 2016, 11:45:41 PM

Title: "faking" a 350K pot with an audio taper
Post by: MarkL on April 17, 2016, 11:45:41 PM
Am I right that if I take a 500KB pot and put a 1.2M fixed resistor across lugs 1 and 3 of the pot, the result will basically be a 350KA pot?

Or am I miscalculating things in terms of the taper/curve?
Title: Re: "faking" a 350K pot with an audio taper
Post by: alanp on April 18, 2016, 01:14:30 AM
http://www.diystompboxes.com/analogalchemy/emh/emh.html (http://www.diystompboxes.com/analogalchemy/emh/emh.html)

This is the calculator I use. It didn't like the 500kB value, but a 1mB pot yielded 850K and 38K to get a 350kA pot.
Title: Re: "faking" a 350K pot with an audio taper
Post by: midwayfair on April 18, 2016, 03:39:45 AM
You cannot fake an audio taper with a variable resistor. You can if it's a voltage divider.

Putting the resistor from 1 to 3 will give you a smaller value pot but the overall taper will be reverse log-ish.
Title: Re: "faking" a 350K pot with an audio taper
Post by: MarkL on April 18, 2016, 08:21:15 PM
John, thanks for the insight.  How would you suggest I then go about modifying a fuzz volume control to approximate a 350K audio taper if I've got a 500KB pot or a 1MB pot?
Title: Re: "faking" a 350K pot with an audio taper
Post by: midwayfair on April 18, 2016, 09:19:56 PM
What are you building? And why does it need to be 350K as opposed to 500K?
Title: Re: "faking" a 350K pot with an audio taper
Post by: selfdestroyer on April 18, 2016, 10:07:30 PM
Im guessing its a FuzzRite and it can be subbed with a 500KB.
Title: Re: "faking" a 350K pot with an audio taper
Post by: MarkL on April 19, 2016, 02:05:24 AM
Oh...no, it's a fuzz face, and I tried a 500K which was too muddy, and a 250K which was not "full" enough, so I figured 350K would be a good compromise!
Title: Re: "faking" a 350K pot with an audio taper
Post by: MarkL on April 20, 2016, 01:10:04 PM
Quote from: midwayfair on April 18, 2016, 03:39:45 AM
You cannot fake an audio taper with a variable resistor. You can if it's a voltage divider.

Putting the resistor from 1 to 3 will give you a smaller value pot but the overall taper will be reverse log-ish.

So John, would it be best, then, to take a 250KA pot and just tack a 100K resistor to lug 3?