A component many aspired to own once; me included
3 separate bands to limit the pumping . Ime guessing this was used primarily for dynamic range expansion bo ? To try it out for some of the compressed music today [ mp3 etc and cd's ] an avr with a tape monitor loop as described in the manual here would be the go ;
For any other audio like dvd-a or sacd or bluray with lossless tracks I wouldnt use it as your speakers tweeters may not be safe
[ note the caution in the pdf ] These devices were also popular because analog cassette recording had dynamic range and noise limitations so a lower signal level could be put on the tiny 1/4'' and help the dolby nr with tape hiss ; with digital recording now this isnt required and certain avrs have ways to help mp3 and other compressed codecs ...
Easy to set up with a few rca's but dial in a low % if you try it