High-end active preamp system featuring 4 dual-concentric controls for Bass/Treble, Mid/Freq, Volume/Blend, and Passive Tone. Integrated performance features include a 'Pull for Bright' treble function and a 'Push-Pull' active/passive selector on the tone pot. Includes the full modular wiring harness, internal gain trim pots, original manual, and chrome knurled knobs.