Potentiometers: what do you suggest??

Terry Bowman terrymbowman at rica.net
Tue Jun 10 07:21:46 CEST 1997

The "A" indicates that the pot is linear taper. "B" indicates audio taper.

Mouser and Radio Shack pots are definitely NOT the same unless RS changed
manufacturers recently. Furthermore, I've always heard that RS pots have a
dead zone at the CCW end of travel; the resistance doesn't change at all
for quite a few degrees. Mouser pots don't seem to have this problem.

I guess this is a case of you-get-what-you-pay-for. There're less than a
buck apiece in quantity from  Mouser. I would never use a Radio Shack pot
except in a temporary emergency--they never have more than three of the
same value in stock anyway. The only other choice is to spend a LOT more
money. If you're building a custom system for a rich composer or something
that's going on the road I guess it's worth going first class...

Finally, in the interest of idiotic completeness, the pots in question are
24mm, not 1", or so says the Mouser catalog.

>dave.halliday at greymatter.com (Dave Halliday) writes:
>> >> I really like the Mouser brand pots with the 1" diamater assembly.  Yes,
>> >> they are pretty big and take up a lot of space on your panal, but they
>> >> are only a buck each and the action is on them so right-on.  Besides
>> >> being silky-smooth, they are the kind of pots that once you start moving
>> >> them, they have some momentum so that you can do really smooth sweeps.
>> >     You mean the ones with the "a" in a circle on the back?  I got one of
>> >     those at Radio Shaft many many years ago and stuck it in a wah pedal.
>> >     It went scratchy extremely quickly.  I still have some that are about
>> >     13 years old and have barely been used and they even feel scratchy.
>> Mouser is a mail-order vendor and probably not the place where RS got
>> their parts.  Mouser ( as well as DigiKey - my other favorite place )
>> sell only first-run, non-surplus, quality components.
>I certainly didn't mean to imply that RS got their pots from Mouser.
>But, could it be that they both get their low-cost pots from the same
>manufacturer?  I would guess the original poster is referring to pots
>similar to Mouser stock # 31VJ301 (p.180 of the latest catalog).  I
>believe these are the pots that came with my Theremax kit (they look
>like the picture and are stamped "MOUSER" on the back).  Also, my
>Theremax pots look exactly like a 16mm pot I bought from Mouser only
>bigger and the 16mm pot is not stamped MOUSER."
>Both the Theremax kit MOUSER pots, the 16mm Mouser pot, and my old Rad
>Shaft pots have a lowercase "a" in a circle on the back, which as far
>as I can guess is the manufacturer's logo.  Furthermore, my old RS
>pots have "ALPHA" stamped on them.  Guess what?  Look in the latest
>Mouser catalog on p. 180 and you'll see (top of the page) that "a"
>logo with ALPHA underneath.  Looks like the same manufacturer to me.
>The exterior of the 24mm and 16mm Mouser pots is *slightly* better
>than the Rad Shaft pot (but very similar).  But who knows what lurks
>inside.  I'm not sure I'd commit one to heavy duty use like a filter
>cutoff frequency control.  There's gotta be a reason they're so cheap,
>and when you're buying 50 or 100 price is definitely an issue.

Terry Bowman, KA4HJH

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