Tape Saturator

A stereo tape-style saturator. It rounds transients, thickens mids, and adds the warm, gently compressed grit of signal pushed into magnetic tape — from a subtle sheen on a mix bus to full, crunchy overdrive on a single voice.

How it works

Each channel passes through a Langevin saturation curve — the same soft-knee shape that models tape's response to hard signal. Before saturating, the high band is briefly emphasized and then pulled back down afterward, so harmonics bloom from the body of the sound rather than just the top. A separate warmth filter then rolls off the highs to taste, and a DC blocker keeps the output centered. The two channels run as fully independent saturators, so stereo width is preserved.

Controls

  • Drive — how hard the signal hits the tape, from a clean polish to saturated breakup. Higher settings also push more high-frequency emphasis for a brighter, more aggressive bite.
  • Warmth — a low-pass that darkens the saturated tone, sweeping from open and present down to a muffled, old-tape character.
  • Mix — blends the saturated signal against the dry input; pull it back to dial in just a touch of color.
  • Bias — sets how asymmetric the saturation curve runs, sweeping 0x for a symmetric, odd-harmonic edge through the neutral center up to 2x for fatter, even-harmonic tape warmth.
  • Edge — scales how hard the highs are pushed into the saturator before being pulled back, from 0x for a smooth, rounded top to 2x for extra sheen and presence; a brightness-into-distortion axis that complements Warmth's darkening.

Inputs & outputs

  • In L / In R — the stereo signal to saturate; patch a mono source to one for parallel-mono use.
  • Drive / Warmth / Mix / Bias / Edge CV — voltage control over each knob; patch an LFO or envelope to modulate drive swells, rhythmic warmth, or shifting tape character.
  • Out L / Out R — the processed stereo output.

Tips

  • Keep Mix below full for a parallel-saturation glue effect that fattens without smearing transients.
  • Modulate Drive CV from an envelope so louder hits saturate harder — a fast, musical way to fake tape compression.