Dark3A

Dark3A — Solid-State Optical Leveling Amplifier

A schematic-accurate emulation of the legendary Universal Audio LA-3A — the solid-state cousin of the LA-2A. Same iconic T4B photocell, but with a transparent solid-state gain stage instead of a tube — giving you the smoothest opto compression with a cleaner, more modern voicing. The vocal compressor that defined countless hit records.

Authentic LA-3A character:

• T4B Photocell — dual-stage release with program dependency
• Solid-state gain stage (transparent, no tube coloration — the LA-3A’s defining feature vs LA-2A)
• UTC transformer modeling on the output
• Hardcoded ballistics — single voicing tuned for the transparent LA-3A character (no mode switching)
• R29 H.F. Contour — authentic LA-3A high-frequency compression contour (0 = flat, 100 = up to ~10 dB more GR at 15 kHz than at 1 kHz) for de-essing-style frequency-selective compression
• CLASSIC (Feedback) vs MODERN (Feedforward) detector topology

Core controls (LA-3A faithful):

• Gain (0–40 dB) and Peak Reduction (0–100, like the hardware)
• Compress / Limit mode switch
• HF Emphasis sidechain tilt
• H.F. Contour — the LA-3A’s signature frequency-dependent gain reduction
• Stereo Link for L/R coupling
• Mix for parallel compression

Pro extras:

• 6-band Sidechain EQ — full parametric (Bell / LShelf / HShelf / LCut / HCut)
• 6-band Output EQ — full parametric, post-compression
• Three optional transformers: Carnhill / Sowter / Cinemag
• Saturation drive
• Knee, Input Gain, Sidechain HPF (0–500 Hz)
• Auto Gain Compensation
• x2 / x4 / x8 Kaiser FIR oversampling
• GR / Output metering modes