Input. Trim drives the preamp as a color control, with the gain taken back out afterwards. Mic position puts far more gain in front of the stage and finds the rails sooner than Line.
EQ. Center-detented Treble and Bass faders, shelving at 10 kHz and 100 Hz, plus or minus 10 dB.
Tape. Drive sets how hard the signal hits the oxide. Bias trades treble against grit in both directions. Tape Type I is ferric — it runs out of headroom sooner and keeps more energy in the mids; Type II is chrome, holding more treble and taking more level before it gives way. Noise injects hiss where the expander can breathe on it, and Wobble is master depth over wow and flutter.
dbx, speed and bounce. Type-II companding can be switched out, which means far more hiss and no breathing. Tape speed runs 3-3/4 or 1-7/8 ips — half speed halves the treble and raises the hiss. 2nd Gen bounces the signal through the tape a second time.
Output. Mix is a time-aligned dry/tape blend; Output is a center-detented plus or minus 18 dB trim.
Behind the DOOR. A service panel the front owners were never meant to open: head bump, azimuth, crosstalk, dropouts, pitch, and the wow/flutter balance — plus a hidden tape echo with send, time, repeats, tone and return.