Just picked this up. A beauty in what seems to be fully working condition. I know folks like these 70's receivers but there's no manual on HiFi engine. Nice phono section but I get a buzz if I use an external phono preamp. Just wondered if the turntable should be grounded to the Sansui instead of the preamp. It's huge and around 50 lbs. German first pressing of Second Helping, by the way.