Locomotive Audio Power-MU SEPIA Module

What is the Locomotive Audio POWER-MU is a full-valve modular vari-mu dynamics processor for the SEPIA platform, operating on ±17 V DC rails and delivering classic variable-mu compression behaviour with modern control, stability and headroom in a compact modular format.

Overview

The POWER-MU marks Locomotive Audio’s first modular design for the SEPIA platform and introduces a fully valve-driven vari-mu compressor engineered to meet contemporary studio demands without abandoning the musical behaviour that defines classic tube compression. The design draws directly from revered vari-mu topologies while refining them for modular integration, consistency and extended dynamic control across a wide range of sources.

Valve Architecture and Compression Behaviour

The POWER-MU uses a true valve gain reduction stage where compression depth responds organically to signal level, producing the smooth, program-dependent behaviour associated with classic vari-mu compressors. This topology delivers gentle compression at low ratios while naturally increasing control as input level rises, allowing the unit to remain transparent under subtle settings and musically dense under heavier gain reduction. The valve path introduces harmonic complexity that enhances weight, depth and perceived loudness without obscuring transient detail.

Modern Control and Stability

While rooted in traditional vari-mu design, the POWER-MU integrates modern component tolerances and power regulation to ensure reliable performance within a modular environment. The ±17 V DC rails provide consistent headroom and operating stability, allowing the valve stages to perform predictably across sessions. The updated control architecture enables repeatable settings and tighter response compared to vintage units, making the module suitable for precision mixing as well as character-driven processing.

Source Versatility

The POWER-MU handles a broad range of material with equal authority. On vocals it delivers density and intimacy without audible pumping. On drums and percussion it adds cohesion and weight while preserving attack. On bass and synths it enhances sustain and harmonic richness. Across buses and stems it provides glue and dimensionality that remain musical even under significant gain reduction.

Integration with the SEPIA Platform

Designed specifically for the SEPIA ecosystem, the POWER-MU maintains a compact footprint while delivering full valve performance. The modular format allows users to integrate vari-mu compression into flexible signal chains without sacrificing analogue authenticity. The unit complements both clean and coloured modules within the platform, making it suitable for hybrid workflows that demand both precision and character.

Build Philosophy

Locomotive Audio engineers the POWER-MU to function as a long-term studio tool rather than a nostalgic replica. The design prioritises signal integrity, thermal stability and consistent performance while preserving the tonal depth and dynamic behaviour expected from valve-based compression. Every aspect of the circuit serves musical response first, ensuring the module remains relevant in modern production environments.

Why Choose the Locomotive Audio POWER-MU

• Adds depth, weight and cohesion without flattening dynamics

• Delivers classic valve compression character with modern reliability

• Adapts naturally to vocals, instruments, buses and full mixes

• Enhances perceived loudness while retaining musical movement

• Integrates seamlessly into modular analogue workflows

• Fully valve-driven vari-mu compression circuit
• Designed for the SEPIA modular platform
• Operates on ±17 V DC power rails
• Program-dependent compression behaviour
• Smooth gain reduction with musical saturation
• Modernised control and component tolerances
• High headroom for professional studio use
• Suitable for individual sources and bus processing
• Compact modular form factor
• Engineered for long-term reliability and consistency

This item, like everything we supply, comes with the complete support of our expert team. Our excellent technicians have been specifying, building and supporting studios for over twenty years. If you have any problems with installation, setup or everyday use, they’re never more than a click away, and always happy to help.

You can contact them here.