SR&D, Rockman x100 by Tom Scholz.

Note: Does not include original power supply. https://www.rockman.fr/Manuals/X100.pdf The SR&D Rockman X100, designed by Tom Scholz of Boston, was a revolutionary 1980s headphone amp and preamp known for creating iconic, polished arena rock tones with built-in compression, chorus, and echo, allowing guitarists to get studio-quality sounds easily, featuring four modes (two clean, two dirty), and now recreated by MXR as an analog stompbox that preserves its classic, "chorusy," compressed sound for modern rigs Key Features & Description Origin: Original units by Scholz Research & Development (SR&D) in the 1980s; Sound: Captures the quintessential "80s arena rock" sound, famous for Def Leppard's Hysteria album. Core Tones: Features four modes: CLN2: Crystal-clear clean. CLN1: Punchier, mid-focused clean. Edge: Moderate, gain-sensitive clipping. Distortion: High-energy overdrive with sustain. Effects: Includes classic compression (slow release for clean, fast for dirty) and shimmering bucket-brigade chorus. Controls: Simple Input Gain and Volume sliders to shape tone and levels. Format: The original was a headphone amp with recording connectivity;