Pots.... dual?

[jlullo]

I am ordering all the parts for my tonepad tube screamer, and i'm stuck on Potentiometers.    I need a 20k lin, 500k log, 100k lin.  I found all three on Futurlec.com, but am given the choice of linear, log, or dual linear and dual log.  what is the difference, and what would work best?

thanks!

[petemoore]

I found all three on Futurlec.com, but am given the choice of 
linear, The pot's wafer has 'symmetrically' apportioned resistances from wiper

to outside lugs[/b]
  log, This is short for "Analog", often used in volume controls to compensate for human hearing quirkiness, and has an 'assymmetrical' apportionment of the Resistances...it's like a linear in that 0k - 100k variable resistance is available from wiper to either side, but the 'assymetry' involves a greater resistance increase per unit of shaft turn at one end of the shaft's travel, less resistance change at the other
  or dual
  This is two pot assemblies on 1 shaft. Each pot has 3 lugs and they share the shaft to turn their wipers, sometimes called 'tandem'.
  linear and dual log. Two pots share a shaft, lin and log refer to taper of the potwafer.
  GEO "Secret life of Pots"

[jlullo]

so then, for most applications, you don't want a dual pot, right?

[Mark F]

Right.

[jlullo]

great!  thanks guys!

[QSQCaito]

log, This is short for "Analog

I though it was for logarithmic, because they had a logarithimic travel.. just as our ears.. our ears don't hear lineal

bye bye

DAC

[petemoore]

  Ok...logorythmic...log...or analog...
  I think they all are just different names for an analog or logorythmic taper.

[d95err]

  Ok...logorythmic...log...or analog...
  I think they all are just different names for an analog or logorythmic taper.

Logarithmic pot taper is sometimes marked as "A". This is for Audio, nothing else. There is no pot taper called "analog".

An "A" marking on a pot does not have to mean Audio or log though. Some companies use A for linear, B for log, etc. The only way to know the taper of an unknown pot is to measure it.

[mjones99]

There are Linear, Log A, and Log B tapers, as far as I know.  The Log B is the reverse taper of a Log A.  Some amps use Log B tapers to get a correct amount of travel on tone controls.  I think there is a way to change a Log A taper to a Log B by adding a resistor across the pot but I forget the specifics.