Substituting c500 for a500 pot in pedal, any bad effects I should expect?

[davepedals]

As my subject describes...  I need an A500k linear pot for a pedal project, any bad effects using C500k anti-log?
Thanks for any help!


Dave

[ElectricDruid]

Nothing will blow up, if that's the type of bad effects you're afraid of.

The control's response will be all wrong is the only trouble. If it's log/anti-log instead of linear, you'll find that most of the change happens in a small range at one end of the pot. Depending what the pot controls, that might be more or less serious.

But it'll let you get the circuit up and running, and you can always swap the pot later on.

HTH,
Tom

[bool]

the only bad side-effect would be "this knob dosent react the way it is supposed to" comments from the user

...but no technical bad effects whatsoever

[davepedals]

Thanks, I'll get started then!
Dave

[Mark Hammer]

Flip the outside lug connections and legend the control in reverse.

So, f'rinstance, a great many LFOs use an anti-log "C" pot for rate adjustments, since it provides a nice degree of rate dialability.  That assumes that clockwise is faster.  Use a regular log pot, with the leads flipped, and you get the same dialability but in reverse.  That is, clockwise is slower.

[davepedals]

Thanks for the info, Mark. I'll give that a shot!


Dave

[ElectricDruid]

Flip the outside lug connections and legend the control in reverse.

So, f'rinstance, a great many LFOs use an anti-log "C" pot for rate adjustments, since it provides a nice degree of rate dialability.  That assumes that clockwise is faster.  Use a regular log pot, with the leads flipped, and you get the same dialability but in reverse.  That is, clockwise is slower.

You can often relabel things to make a back-to-front pot make sense. "LFO rate" becomes "LFO period", "Treble boost" back to front is "treble cut" etc etc

T.

[duck_arse]

delay?

[deadastronaut]

i'm always using log pots backwards...it works fine.

saves ordering ''special'' pots..

[davent]

As my subject describes...  I need an A500k linear pot for a pedal project, any bad effects using C500k anti-log?
Thanks for any help!


Dave

I'm confused as to what type of pot you don't have, i see A500k and i assume audio pot. Like others have said i too use audio/log pots wired with the outside wire swapped regularly in place of called for antilog/C pots.

dave

[davepedals]

Like I said, I have a log pot, I need an audio pot.  My question has been answered now, and I really  appreciate all the help. Dave.

[davent]

Like I said, I have a log pot, I need an audio pot.  My question has been answered now, and I really  appreciate all the help. Dave.

Hi Dave,  Log pot and an audio pot, two names for the same thing.



dave

[davepedals]

Wow, I knew I made a mistake somewhere in this post... Of course I meant a linear pot. I'll blame it on too many late nights!  Should've mentioned in the first place I'm building a Woodrow pedal. Thanks a bunch.


Dave

[LightSoundGeometry]

Flip the outside lug connections and legend the control in reverse.

So, f'rinstance, a great many LFOs use an anti-log "C" pot for rate adjustments, since it provides a nice degree of rate dialability.  That assumes that clockwise is faster.  Use a regular log pot, with the leads flipped, and you get the same dialability but in reverse.  That is, clockwise is slower.

learn something new everyday!  I never plotted a graphical response of pots myself but from some very minor research a long time ago thought the curves were off too much to sub one for another, always tried sticking to the schematic. I have used weird values before on things with no effects and other times terrible results.

on a side note about pots..the hard rotation and stickyness of taydas alpha pots come from being dirty and just need cleaned? and if so, whats the best way to clean a new pot without damaging it?

thanks in advance

[davepedals]

I use detoxit, or detoxit gold to clean pots.

[ElectricDruid]

on a side note about pots..the hard rotation and stickyness of taydas alpha pots come from being dirty and just need cleaned? and if so, whats the best way to clean a new pot without damaging it?

The stiffness of new pots is usually because they pack them with grease. You're not supposed to clean it out. They're certainly not dirty.
That said, if you want them looser, cleaning it out with something like deoxit would probably work fine.

Tom

[Mark Hammer]

Flip the outside lug connections and legend the control in reverse.

So, f'rinstance, a great many LFOs use an anti-log "C" pot for rate adjustments, since it provides a nice degree of rate dialability.  That assumes that clockwise is faster.  Use a regular log pot, with the leads flipped, and you get the same dialability but in reverse.  That is, clockwise is slower.

learn something new everyday!  I never plotted a graphical response of pots myself but from some very minor research a long time ago thought the curves were off too much to sub one for another, always tried sticking to the schematic. I have used weird values before on things with no effects and other times terrible results.

on a side note about pots..the hard rotation and stickyness of taydas alpha pots come from being dirty and just need cleaned? and if so, whats the best way to clean a new pot without damaging it?

thanks in advance

1) As noted by Tom/Druid, new pots are not dirty.  As such conventional contact cleaner sprays are not necessary to improve the quality of contact, but they do have the ability to lubricate an otherwise stiff pot and make it rotate more smoothly.  To do this, you don't need fancy schmancy contact cleaner.  Something like one of the Caig Deoxit varieties won't hurt anything, but isn't really necessary for new pots.  If all you can score locally is something from Radio Shack or whatever, don't sweat it.

2) The cheaper the pot, the more the taper is like a pretty good guess, and the less it is like a promise.  I'm sure $40 audiophile pots stick very close to the declared specs of whatever taper they are configuredfor.  The 50-cent pots, not so much.  That doesn't mean one should completely ignore taper on small Alpha pots.  But don't expect it to be precise. 

2)

[davepedals]

I wish we still had a RadioShack, they have all gone out of business in most places.

[duck_arse]

old stiff pots can be de-stiffened by contact cleaner-ing in through the vent under the wafer (hold it shaft downwards) until it runs out the shaft, taking the old grease with. the problem will now be that the shaft turning is too loose.

[dbp512]

I wish we still had a RadioShack, they have all gone out of business in most places.

And the ones that aren't out of business, I wish they were... When I started building last year I needed a few parts, so I thought I'd run to my local 'shack, since I remembered as a kid they'd have row and row of shelves containing every part I could ever need in a pedal. But when I got to the store the employee was trying to convince me to upgrade my phone by joining whatever sketchy network they were selling. I told him what I needed and he just shrugged and gestured to one dainty little shelf in the back