boost in the last 3/4 of pot ?

Started by ward, November 01, 2006, 12:40:39 PM

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ward

Quote from: markm on June 20, 2006, 10:47:17 PM
Quote from: Pushtone on June 20, 2006, 09:57:43 PM

Yeah, the volume control on my GGG build had all the "BOOST" crammed up in the last 3/4 of travel. Same for the GGG MosFET boost.
I must be missing something. ???

Yeah, my Mosfet is the same.
I'm really using it as a vol. biist for lead work.
Jack has a mod for it on his site about making the Mosfet Boost into
a Booster/Buffer.
I may give it a try.
BTW, I tried a bunch of pots and all had the same result.
Jack has an article on the reason why the Mosfet vol control behaves the way it does.
Interesting read.


Exactly how mine is behaving.
Is there a cure ?
Is the article still up ?  Can't seem to find it .

Mark Hammer

The "perfect" pot taper that makes all customers happy will likely never exist.  Some people are more interested in dialing nuances at the low end, some more interested in nuances at the high end of the range, and others interested in the entire range of the control.  As a result, it will be difficult to identify a pot taper where there is just the right amount of dialability in the control to make everyone happy.

One strategy is certainly to use some sort of pre-tapered pot that matches he function well.  Another is to create a pot taper by means of parallel resistors, à la "Secret Life of Pots" (at www.geofex.com).

A third strategy is to simply divide up the entire range of control into "zones" of interest, and use a toggle to select them, in tandem with a pot to fine tune them.  In the case of the MosFet booster, for example, a 5k pot with a 6k8 parallel resistor serves as a tailored 2k9 pot.  Use a toggle that switches a 2k7 fixed resistor in series with it, and you've split your overall 5k range into two zones where the entire rotation of the pot can be useful to you.  The same strategy can be used in many areas - divide and conquer.

Pushtone

Help is on the way ward.

From this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=49838.0

This quote from Small Bear.
Quote from: smallbearelec on September 28, 2006, 09:05:51 AM
Jack has asked me to get Alpha to make a 16mm 5K reverse audio pot, and I will do so. Parts will be available shortly after New Year's.

Regards
SD

It's time to buy a gun. That's what I've been thinking.
Maybe I can afford one, if I do a little less drinking. - Fred Eaglesmith