Antilog pots

KA4HJH terrymbowman at
Fri Jan 30 04:45:04 CET 1998

>The Dark force of dance wrote:
>> You would need to obtain the fairly rare, _Anti-log_
>> taper pots to give a reasonable range of adjustment from maximum to minimum.
>Rare? I couldn't get them anywhere yet. Maybe as a replacement part from
>mixing console manufacturers, I didn't try that.
>But I've found a way to get anti-log potmeters for my SSM2017-based
>microphone preamps:
>Use a Piher PC16 log potmeter, drill carefully a few mm deep with a 4mm
>drill into the back until the plastic shaft can be pulled out. Then
>drill very caryfully a little further, but *not all-way through*. The
>shaft has sort of a little cog wheel at its end. If you drill too deep,
>there is nothing left this cog wheel can "grip" into.
>Now it can be inserted at the back side of the potmeter. It is quite
>stable if you didn't drill too deep.
>Of course, the potmeter cannot be front panel mounted in the usual way
>anymore. But it can be mounted on a pcb parallel to the front panel.

Why not just drill a hole in the back end of the shaft and epoxy a new
shaft onto the rear? Might work with the right pot if you can get it
centered up properly.

I've found that on a couple of occaisions that wiring up a log pot
backwards (in a circuit that wants to go from high to low resistance) gives
a more useful response than a linear pot -- you just have to live with a
backwards control. But of course that's a different situation entirely.

Terry Bowman, KA4HJH

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