Hi & Low Pass filters Schematics

I'm new to this forum so hi all  ;D

I think the title says it all. I need second order variable hi and low filters. I'm not a circuit designer so I can't make it up myself and I also haven't been able to find much on the web. Using the search function I found this thread: http://www.groupdiy.com/index.php?topic=8986.0

A guy posted schematics of a calrec filter but sadly some of the values for the low pass filter are unreadable.

Any help would be greatly appreciated!

Don Lancaster's active-filter cookbook

might be a starting place

Thanks for the reply. Actually I don't have access to that book  :'( I was hoping someone could just post a link to other schematics or give me the missing values for those resistors and capacitors in the schematics

Oldie but goodie:

http://www.d-r.nl/dnrsite/pdfmanuals/HI-LowpassFilter-Manual.pdf

Needs dual-revlog for freq, but you could also use dual-deck rotary switch.

Or most practical: use normal dual-logs that you turn from 22:00 (min-freq) via 18:00 to 02:00 (max-freq). 
You in fact turn the knob anti-clockwise for increasing freq, but using this trick you still maintain the left-to-right feeling.

Bye,

  Peter

Search here about harrison filters, they sound great. 

Thank you guy, it's been very helpful so far. Is there any chance I can find the schematics for the SSL filters ?!?  :