Sweep problem on 100kA pot

Started by H5N1, August 01, 2009, 08:47:42 PM

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H5N1

I just built a two knob Cream Pie, using an OC140, and the 100kA gain pot has an issue:  The entire range of the pot is crammed into the last 1/4 turn.  What to do?

anchovie

Reverse the wires on the pot. If the sweep is acceptable (though of course with the rotation being in the opposite direction) then replace it with a 100k reverse log pot.
Bringing you yesterday's technology tomorrow.

H5N1

Tried switching the wires: same thing only different.  Wondering if I could change the value of the pot to make the sweep a little more broad?  Tried 50k, but that might be the wrong direction, I'm not really sure.

BAARON

Reversing the wires on the pot won't change anything.  If it's only affected by the last part of the pot's sweep, then you've got an unsuitably tapered pot.  If you can, try a 100k linear pot before you try a 100k reverse log.
B. Aaron Ennis
If somebody makes a mistake, help them understand what went wrong.  Show them how to do it right.  Be helpful.  Don't just say "you're wrong, moron."

anchovie

#4
My apologies, I'd got back really late from a festival and it made sense in my head at the time!

A reverse log would still be worth a try if a linear isn't quite there. Or maybe a smaller value pot in conjunction with a resistor to make the total 100K.
Bringing you yesterday's technology tomorrow.