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Projects => General Questions => Topic started by: cajone5 on October 13, 2016, 02:43:35 PM

Title: Reversing the sweep on a potentiometer... do I need to reverse the taper too?
Post by: cajone5 on October 13, 2016, 02:43:35 PM
So I am wiring up a tremshifter and the filter and trem rate pots in the existing schematic are wired such that the highest rates are full counter clockwise.  I would like that to be fully clockwise for my simple brain to more easily grasp the function of the controls.  The recommended wiring for these controls treats the pot like a variable resistor if I understand correctly (one wire to lug 1, the other two to lugs 2 and 3 as shown in the link below).  Both controls use an A1M pot.

http://effectslayouts.blogspot.com/2015/12/deadastronaut-tremshifter.html

(http://4.bp.blogspot.com/-0x7DXfgcjNY/VuHkGuL2a4I/AAAAAAAACqg/WTVjItBONLM/s1600/DeadAstronaut%2BTremshifter.png)

(http://2.bp.blogspot.com/-BaWUu29G7dM/VWSw1Vc0l9I/AAAAAAAAFDU/JHBU0Ju0zOI/s1600/Screen%2BShot%2B2015-05-26%2Bat%2B1.41.23%2BPM.png)

So, if I want to reverse the sweep, I believe I can just modify the wiring to have the first wire connect to lug 3 (instead of 1) and the second wire connect to lugs 1 and 2 (instead of 2/3).  However, since it's an "A" log-taper pot, would i need to use a "C" reverse-log-taper pot as well to get similar performance?  I am thinking I would but am not sure and was hoping someone smarter than me could shed some light here.

Could anyone verify/clarify?  I know I could test one with my multimeter and plot the results but would rather know before ordering.  Thanks madbeaners.  ;)
Title: Re: Reversing the sweep on a potentiometer... do I need to reverse the taper too?
Post by: Leevibe on October 13, 2016, 03:02:33 PM
Yes. You can get the pot to work in the direction you want, but as you suspect, you will also need to use a C taper pot to get the same response curve.
Title: Re: Reversing the sweep on a potentiometer... do I need to reverse the taper too?
Post by: cajone5 on October 13, 2016, 04:12:44 PM
Thank you sir -- looks like I need to order more parts... so it goes.