Manley Stereo Variable Mu® Limiter Compressor - High-End Tube Dynamics Processor
The Manley Stereo Variable Mu® is a world-renowned all-tube stereo limiter/compressor, favoured by top mastering engineers and mix professionals for its musical compression, rich harmonic content, and unmatched tonal smoothness. Built with Manley's classic hand-wired tube circuitry, the Variable Mu offers transparent dynamic control at low ratios</strong>. lush analogue coloration when pushed - making it a go-to for everything from gentle bus compression to full-on analogue glue.
A true modern classic, the Stereo Variable Mu® uses a real variable gain tube (the 5670 dual triode) to achieve compression - hence the name “Variable Mu.” Its dual-channel design with stereo link functionality makes it ideal for stereo buses, mix buses, or mastering chains. With switchable limit/compress modes, With its unique design, independent threshold and gain controls, and carefully selected components, this unit delivers the kind of analogue warmth and dynamic control that digital plugins simply can't replicate.
Key Features
- All-tube stereo limiter/compressor with hand-wired point-to-point construction
- True variable mu design using 5670 vacuum tubes
- Switchable Compress (soft-knee, 1.5:1-3:1) and Limit (harder knee, 4:1-20:1) modes
- Independent Threshold and Gain controls per channel
- Switchable stereo link for master bus and mastering applications
- Bypass switch per channel for direct signal comparison
- Balanced XLR and 1/4” TRS inputs and outputs
- Premium components: custom Manley transformers, ALPS potentiometers, and high-quality tubes
Technical Specifications
- Channels: 2 (Stereo or Dual Mono)
- Compression Ratios: Variable; approx. 1.5:1 to 20:1 depending on mode and threshold
- Attack Time: 25 ms - 70 ms (programme-dependent)
- Release Time: 0.2 sec - 1.5 sec (programme-dependent)
- THD: <0.3% @ +20 dBu output
- Noise Floor: -85 dB typical
- Inputs/Outputs: Balanced XLR and 1/4” TRS
- Tubes: 2x 5670 (gain), 2x 5751 (sidechain), 2x 7044 or 12BH7 (output)
- Power: 90-250 VAC, 50/60 Hz (universal input)
- Dimensions: 2U rackmount (19″ x 3.5″ x 10″)
- Weight: Approx. 16 lbs (7.3 kg)
Ideal For
- Mix bus compression with analogue warmth and glue
- Mastering applications requiring tonal shaping and stereo cohesion
- Vocal, drum, and instrument tracking with natural tube compression
The Manley Stereo Variable Mu® is the definitive tube compressor for serious professionals - delivering iconic tone, powerful control, and timeless character in studios where sonic quality is non-negotiable.