If I remember correctly, their two channel and mono amps of that period were made by Coda and the Powerbloc 5 was made by Enlightened Audio Designs. The Luminance amp was made by Proton. I owned a Powerbloc 5 at one point and thought it to be a good amp. I liked the Aragon 8008 x 5 better. The manual for it is available on the Legacy site.
https://d2digq31msfd9c.cloudfront.net/uploads/manuals/powerbloc5.pdf?mtime=20210224113318&focal=none