Adcom Preamp...what is 'contour' button for?

This amp (555 GFP) has a 'contour' button that seems to only boost bass output. Is that its only purpose?
It's a loudness control.,Boosts the treble and bass
If you don't have a manual you can download one from Adcom's website.
The contour button must be depressed, if you want the high and low filters to work. If you need a user's manual, provide me with a fax number and I can fax you a copy. I have a 12 year old Adcom Tuner/Preamp.

its basically a loudness button without havivg to tell anyone you have a loudness button on your high end amp
Can anyone help??I have the same pre amp (Adcom GFP 555II) and was wondering- because I am not home to look at it- does it have sub out jacks?? thanks, Dave

I have the "I" version ... which did not have a sub out (they really weren't used much in 1989). Check Adcom's website as they have downloadable user manuals.