Bill; that should be 8 db rather than 9 db for a standard two position switch.
Michael; Bill is right, your setup is apparently volume, pan, filter, Q switch. The following is cut from a previous post:
Basically, the filter control is a low pass filter; as you roll it back it lowers the point at which it passes low frequency signals and blocks high frequency signals. To quote Mica, the range is from 350Hz-6KHz. Wherever you set the filter, only frequencies below that cutoff point are passed. The Q switch works in concert with the filter and provides an 8db boost at the cut off frequency you've set with the filter. When the switch is off you get a flat response up to the filter setting. Again to quote Mica, the Q affects mainly the attack portion of the note.
Mica; nice pics!
Jeff; for my S1, my F-1X is set at 5, 5, 5 1/2. When I plug my six string Essence in, I drop the treble down to 5. It's amazing how much of a difference there is between 5 and 5 1/2.