There were some posts on the old forum concerning the Crown VFX-2A. During the time the forum was down I was able to aquire a VFX-2A schematic. I can send this schematic to those who are interested once I get it scanned in.
The Crown VFX-2A is one very sweet bi-amp/tri-amp filter. 18 dB/octave Butterworth high pass/band pass/low pass filters continuously variable from 20 Hz to 20 kHz.
If you install polystyrene and foil or polypropylene and foil bypass capacitors in parallel with all the series output electrolytics you step up from "very good" to "excellent" sound quality. For those who prefer minimal "electronics" in their circuit paths the Crown VFX-2A is tough to beat.