DarkVar

DarkVar

A faithful emulation of the Manley Variable-Mu — the classic vacuum-tube stereo bus compressor/limiter prized for its smooth, “glue”-style tube compression on mix buses, drum buses, and mastering. DarkVar reproduces the variable-mu tube character, the dual COMP/LIMIT behavior, and the hardware’s true dual-mono mode (separate L/R strips), with added tube-warm output EQ, sidechain EQ, parallel mix, and transformer color.

Top panel — main compression

INPUT LEVEL (−8…+8 dB, stepped) — Drives signal into the tube stage; matches the hardware’s 9-position stepped gain (−8/−4/−2/−1/0/+1/+2/+4/+8).

THRESHOLD (−80…0 dB) — How much compression. 0 = no compression, −80 = most extreme. (Labeled PEAK on the hardware.)

ATTACK (25…70 ms) — Continuously variable attack time.

RECOVERY (5 steps: Very Slow 8s / Slow 4s / Medium 0.6s / Fast 0.4s / Very Fast 0.2s) — Release time.

OUTPUT (−40…+40 dB) — Output makeup trim, unity at 12 o’clock.

COMP / LIMIT switch — COMP = gentle 1.5:1 ratio; LIMIT = harder 4:1→20:1 limiting.

HP SC switch — Engages a high-pass filter in the sidechain (≈100 Hz, 6 dB/oct) so lows don’t drive compression.

LINK / SEP — LINK combines L+R for a stable stereo image (R controls ignored). SEP runs the two channels as fully independent vari-mu compressors with their own threshold/attack/recovery/output/comp-mode/HP-SC and per-channel bypass — the Manley dual-mono mode. (Hence the duplicated R-channel knobs.)

Metering

Dual VU (L/R) — Switchable between GR (gain reduction) and OUTPUT level via Meter Mode.

ADV panel

MIX (0…100%) — Parallel/dry-wet blend.

INPUT (−18…+18 dB) — Tonal input-gain trim (separate from the stepped top-panel INPUT LEVEL).

KNEE (−10…+10):

• negative = harder knee — compression kicks in more abruptly at threshold, snappier/more aggressive.
• 0 = stock — the compressor’s natural vari-mu knee.
• positive = softer knee — compression eases in more gradually, smoother and more musical.

OUTPUT TRIM (−12…+12 dB) — Final output trim.

EQ display + EQ MODE (SC / OUT) — One 6-band parametric EQ display that toggles between two destinations:

• SC — Sidechain EQ: shapes what the compressor’s detector hears, so you can make it react more or less to certain frequencies (e.g. de-emphasize bass so kick doesn’t drive the whole compression).
• OUT — Output EQ: post-compression tone shaping on the audio itself.

Drag bands on the display; per band On, Type (Bell/LShelf/HShelf/LCut/HCut), Freq/Gain/Q.

Transformer (combobox) — Output transformer emulation for added iron/harmonic color.

HQ / Oversampling

HQ (x2 / x4 / x8) — Anti-aliasing oversampling. Default x4.