pot values

[lightningfingers]

does anyone know how to make a 100k pot sound remotely in the region of about 25k?

[Peter Snowberg]

Try attaching 110K resistors from each end to the wiper and then a 47K resistor across the pot's element.

That will get you close.

Code Select Expand

1            2            3

|    110K    |    110K    |
+--/\/\/\/---+---\/\/\/\--+
|                         |
+---------/\/\/\/---------+
           47K
Take care,
-Peter

[lightningfingers]

thanks peter

hate to be a pain but can can you tell me exactly how you worked that out?

[Peter Snowberg]

You're welcome.

A while back I wanted to put together a universal tone stack exploration box. With a typical Fender/Marshall style stack, the most common substitutions are the cap values, but changing the pots is also very common. To avoid having a box with a ton of different pots on the front, I wrote some PHP code to graph out values... building on the trick of affecting taper by the use of a resistor. After much trial and error, I came up with this graph:



The red lines show and ideal linear response, while the black lines show the response with the three resistors added and the magenta lines show the effective total resistance of the combination from end to end.

The pot is assumed to be 1Meg and the two other responses show an effective 500K and 250K.

This is the code if you want it.

Take care,
-Peter