4ms Leveing EQ Amplifier (LEQA)

Optical Compressor and Stereo Equalizer Module - Eurorack Format

• An end-of-chain processor that combines a compressor, EQ, and stereo width in a single module
• Inspired by two studio classics: the LA-2A optical compressor and the Neve 1073 EQ
• Optical compressor with two ratios: 3:1 (Comp) and 10:1 (Limit), with real-time VU meter
• Dry/wet control for parallel compression, with compressor bypass
• Four-band EQ with preselected, musically optimized frequencies
• Stereo Width Processor: narrows, widens, or pushes the signal into “super stereo”
• Mono-to-stereo conversion via a variation of the Haas effect

The 4ms Leveling EQ Amplifier, or LEQA, is the Eurorack module designed for the end of your audio signal chain. It combines into a single module three tools that are normally sought out separately to refine a mix: a compressor, an equalizer, and a stereo width processor. Its design is inspired by two studio classics: the LA-2A optical compressor and the Neve 1073 EQ, both prized for their ability to sound great without excessive complexity. 4ms has taken this philosophy to its logical conclusion: instead of full parametric control, the LEQA works with preset curves and targeted frequency selections to quickly arrive at a sound that works.

LEQA Optical Compressor: LA-2A-Style Musicality

The LEQA’s compressor follows the optical approach, which tends to produce a smooth, musical sound rather than a clinical one. Two compression ratios are available: a gentler 3:1 for general compression and a more aggressive 10:1 for limiting, with a VU meter that displays the applied gain reduction in real time. A dry/wet control allows you to blend the compressed signal with the clean signal to achieve parallel compression, while the compressor can be completely bypassed when not needed.

Four-band equalizer: the Neve 1073 sound in your Eurorack

Next to the compressor is an equalizer featuring low- and high-shelf filters, a midrange bell filter, and a separate high-pass filter—all calibrated to frequencies chosen for their musical response. The LEQA’s EQ can be placed before or after the compressor, or bypassed entirely, thereby changing the way the two sections interact with each other.

Global EQ Gain Control

Global EQ gain allows for subtle adjustments or much more drastic changes, adapting the module to both surgical-precision editing and more creative shaping.

Stereo Width Processor: From Controlled Width to Super Stereo

Stereo management is the third key element of the LEQA. The width processor can narrow an overly wide stereo image, making it more focused, or push a normal stereo signal toward a “super stereo” effect. When applied to a mono source, the LEQA can distribute it across the stereo field using psychoacoustic techniques based on a reworking of the Haas effect.

Manual and CV Control of Stereo Width

Stereo width can be controlled either via a dedicated knob or via CV, allowing the stereo field to evolve dynamically within a patch. The LEQA proves particularly useful for blending a complex patch, fine-tuning a submix, or processing the entire master bus; when pushed beyond standard use, it becomes a creative shaping effect in its own right.

Technical Specifications

• End-of-chain processor: compressor, EQ, and stereo width in a single module
• Optical compressor with ratios of 3:1 (Comp) and 10:1 (Limit)
• Gain reduction and make-up gain controls, real-time VU meter
• Dry/wet control for parallel compression, compressor bypass
• 4-filter EQ: low shelf, mid bell, and high shelf with boost/cut, selectable-frequency high-pass
• Preset frequencies, chosen for their musical qualities rather than based on parameters
• EQ routing before or after the compressor, or bypass
• Global EQ gain for subtle corrections or drastic shaping
• Stereo Width Processor with mono-to-stereo conversion (Haas effect)
• Width control via knob and CV
• Stereo I/O via 3.5mm jacks
• 96 kHz, 24-bit codec, 32-bit internal processing