Drawmer OC1 – 500 Series Optical Compressor

The OC1 brings fully featured optical compression to the Drawmer 500 series range. With a complete control set and advanced shaping tools, it delivers the precision, flexibility, and character you'd expect from a full Drawmer rack-mount unit in a single 500 series slot.

Its optical design offers smooth and natural soft-knee feedback compression with a gentle, programme-dependent response that enhances sources without sounding obvious or over-processed. The result is warm, transparent dynamic control that preserves musicality while adding subtle cohesion and polish.

The OC1 excels on vocals, acoustic instruments, bass, and mix buses where transparency, warmth, and consistency are key.

Total Control

Uncommon in a 500 series compressor, the OC1 offers a comprehensive control set:

• 21-position precision detented controls for accurate, repeatable settings
• Input and Output gain, plus Threshold, Ratio, Attack and Release controls
• Wet/Dry mix control for parallel compression
• PGM mode introduces a second, slower release time that adapts to the programme material above the threshold, reducing pumping and unnatural artefacts during heavy compression
• Comprehensive metering with Gain Reduction, plus switchable Input or Output level on the VU meter
• Hard-wire bypass connects the input directly to the output for completely transparent bypass operation

BIG and AIR Modes

Borrowed from the award-winning Drawmer 1973 three-band compressor, the fully selectable BIG and AIR modes shape the compressor's frequency response, adding extra weight to the lows and enhanced clarity to the highs.

BIG reduces the sidechain's sensitivity to low frequencies, allowing bass energy to pass through the compressor more naturally. This helps reduce unwanted ducking and pumping caused by dominant low frequencies, producing a more open and musical compression response.

AIR preserves high-frequency detail that can often be lost during compression. The result is a more open, detailed, and transparent top end without harshness or artificial artefacts. Vocals become more articulate, acoustic instruments retain their natural detail, and cymbals remain vibrant without becoming splashy.

CRUSH Saturation

The OC1 also features Drawmer's popular CRUSH harmonic saturation circuit. Its effect varies with the input level, adding harmonic richness, subtle saturation, and the analogue warmth that helps mixes feel fuller and more engaging. The low end gains weight, the midrange becomes more present, and the top end retains a smooth, natural sparkle.

Stereo / Group Linking

Using the dedicated Link pin 6 on the 500 series chassis, adjacent OC1 modules can be linked together using the LINK button for stereo or multi-channel operation.

The module applying the greatest amount of gain reduction becomes the master, ensuring all linked units track together accurately. Linking includes Gain Reduction together with the Threshold, Ratio, BIG and AIR functions for consistent stereo imaging and dynamic control.