[sdiy] Vestax multipole potentiometers

[Johannes Öberg]

I'm trying to mod the 3-band EQs on a Vestax PCV-180 DJ mixer, and it
contains these potentiometers with 7 leads on. (they're not mounting
bracket legs, has those too.) They're blue plastic pots with black
plastic D shafts, only markings are "203C 311C".

I found the schematics for a possibly similar mixer, the PCV-02, which
looks like it has the same EQ as the PCV-180.
(http://www.eserviceinfo.com/downloadsm/5709/Vestax_PCV-002.html, page
8 in the pdf)

In the PCV-02 each EQ pot is a stereo 20k, however there's only 6 legs on them.

What does my 7th lead to? How can I find out what each leg on the pots does?

I hope I can avoid desoldering the pots; don't have the equipment to
do that reliably.
I just want to add switches to temporarily short them to their most
CCW position (i.e. frequency kill switch).

/J