Alternatives to a locking potentiometer?

[LeftyStrat]

I want to provide some user-adjustable features in an amp, but I'm worried about the adjustments being accidentally changed. I looked into locking pots, but everything I found is $25-30 for a single pot.

Any suggestions for a mechanism that allows adjustments but not inadvertent adjustments?

[tubeswell]

You used to be able to get those little pots that you adjust with a screwdriver inserted into the recessed adjustment slot, and then seal the recess up with waxy shite.

Don't know if they're still around or not - sorry.

[diagrammatiks]

you can get locking pots one ebay for like 2-3 bucks. it depends on what values you need.

angela has a bunch left in stock as well.

[selloutrr]

If you know what range of resistance your sweet spot is you could use detented knobs with fixed resistance. The benefit would be no matter where the knob is turned it is safe for the amp and user with little to no drift (as long as your resistors are 1% metal film).

If you want a locking traditional rotary potentiometer check webers tech supplies on his website.

[ampdoc1]

I'm assuming you're talking about small internal pots. After you have the setting "tweaked", take some nail polish and coat the top of the pot. You'll be able to move it intentionally with a little twist, but be able to easily match the ends and put it back to the original setting if desired.

Also, if you're in business, this is an easy way to determine if a problem is a manufacturing fault, or due to customer "tweaking".


a'doc

[LeftyStrat]

Thanks guys. Looks like I just need to keep an eye on ebay for the locking pots.

[Structo]

PEC makes locking pots.
I use these for my bias pots.

http://search.digikey.com/us/en/product ... -ND/222796

[img:640:640]http://media.digikey.com/photos/Precisi ... SERIES.jpg[/img]

[Andy Le Blanc]

you can get away with a regular pot inside the unit with a drop of nail polish
or enamel paint to "fix" the shaft, used to used A/B pots but the cost of USA
parts is through the roof

[ApexJr.]

What value are you looking for?

I have some RV4 Allen Bradley in stock...
1K and 1.5K at $2.50 each

Steve @ Apex Jr.

[marshamps]

$1.80 on the Weber VST Website. Also they have 200 Ohm 2 watt and the 10 K bias screwdriver , but non locking.