Enter Sandman

Classic JCM800 pushed hard with a Tube Screamer in front. The key is the Tube Screamer tightening the low end before the amp.

The album rhythm sound was built around James Hetfield’s Mesa/Boogie core, then enlarged with additional amps, nine to eleven cabinets, distant microphones, and multiple rhythm passes. The clean intro is represented with Metallica’s established Roland JC-120-style clean platform, while Kirk Hammett’s solo uses wah into a Boogie/modified-Marshall blend. Exact control positions were not published, so the values below are practical approximations from the documented rigs. Source: Mix Classic Tracks, Guitar.com’s Black Album gear guide, and Guitar World.