X2A Compressor

Description

X2A — Opto Leveling Amplifier

A tube opto leveler in the LA-2A tradition. Slow, forgiving, and hard to make sound wrong.

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Main description

The X2A is a faithful take on the classic tube optical leveler: the compressor engineers reach for when something needs to sit in a mix without sounding compressed.

Its detector is fed from the output of the tube stage rather than the input, exactly as the hardware is wired. That single detail is why the knee stays so soft and why the ratio rises gently with level instead of snapping to a fixed number. It reaches around 3:1 when pushed and stays gentle below that.

The optical cell is modelled as three parallel charge stores rather than one envelope follower. Short transients only charge the fast one; sustained material charges the slow ones too. The release keeps stretching the longer you lean on it, from around 130 ms after a quick burst to several seconds after heavy work. That program dependence is the sound, and here it comes out of the model rather than being bolted on.

The tube stage carries the same behaviour the circuit does. Grid conduction walks the operating point as you push it, so the harmonic balance shifts under pressure instead of just getting louder and dirtier. The supply sags when the amplifier works. The output transformer has real hysteresis, so the core remembers where it has been and colours whatever arrives next.

Second harmonic dominates at low level, where the valve is doing the work. The third takes over as the iron loads up.

Controls

• Peak Reduction and Gain, the two knobs the original had
• Compress / Limit
• Emphasis: tilts the detector towards the top end so bass stops driving the compression
• Mix: parallel blend, phase accurate
• Output trim, stereo link, external sidechain
• Meter switches between gain reduction, input and output
• Oversampling off, 2x or 4x

Specification

VST3, AU and standalone. macOS Universal (Apple Silicon and Intel), Windows 64-bit. Mono and stereo. Full plugin delay compensation, and bypass keeps the same delay so it stays aligned on a parallel path.

Reviews

Free for commercial work. Do not redistribute the installer. Licence · Piracy policy