Manley Laboratories Nu Mu Hybrid Solid State & Variable-mu Compressor

The Manley Nu Mu integrates the T-Bar modified all-tube variable-mu input stage from the classic Variable Mu® Limiter with a solid-state output stage. Combining vacuum tube gain reduction characteristics with contemporary circuit performance. Hand-built in California with custom hand-wound Manley IRON® input transformers and Manley Power® supply technology, the Nu Mu delivers reliable, predictable and musical compression and limiting in demanding tracking and mixing sessions.

Tube variable-mu topology with solid-state output architecture
The Nu Mu's tube-based variable-mu input stage provides smooth compression curves with harmonic characteristics of vacuum tube gain reduction, while the solid-state output path ensures fast transient response and extended bandwidth. This hybrid architecture maintains the dimensional qualities of all-tube compression while delivering the transient accuracy and focused output required for contemporary production across diverse program material.

HIP® control for frequency-selective dynamic processing
The proprietary HIP® (High Impact Preservation) control enables compression of low-level signals while maintaining transient peaks, effectively raising quieter content without attenuating dynamic information. This topology achieves results similar to parallel compression through direct signal path processing, adding density and detail resolution while preserving impact and transient definition across vocals, instruments, and mixed program material.

California craftsmanship with Manley engineering standards
Each Nu Mu is hand-assembled, calibrated, and tested at Manley's Chino, California facility. From custom-wound Manley IRON® input transformers to Manley Power® switch-mode supply technology, every component meets Manley's specifications for sonic performance and long-term reliability. This combination of proven variable-mu topology and modern circuit design continues Manley's three-decade tradition of professional dynamics processing.

• Variable-Mu tube input stage with solid-state signal path
• T-Bar modified all-tube front end derived from Variable Mu®
• Proprietary HIP® control for selective low-level compression
• Hand-assembled in California with custom-wound Manley IRON® transformers

Tube Complement & Compression Features
• Manley IRON® input transformers
• 4 x hand-matched 6BA6 vacuum tubes
• Transformer-Balanced XLR inputs
• Manley HIP function raises soft dynamics without squashing louder passages
• MANLEY POWER® High Voltage Switched Mode Power Supply custom designed for our vacuum tube audio circuits
• INPUT Level Preset 3-way switches -3dB, 0, +3dB
• Continuously variable OUTPUT level controls
• Unity Gain set INPUT to "0" and OUTPUT control to 11 o’clock. (Input source Z= 150 Ohms, Output load Z= 100 kOhms)
• Maximum input level: (1 kHz Sine, <0.3% THD+N)
• -3 = +25 dBu
• 0 = +21 dBu
• +3 = +18 dBu
• Maximum GAIN: 13dB
• GAIN makeup: 10dB (gain above unity)
• Output Headroom: 23dB (referenced to +4dBu)
• Variable ATTACK control: 13msec - 130msec
• RECOVERY switch 5 steps: 0.1s, 0.16s, 0.32s, 0.64s, 1.7sec.
• Continuously variable THRESHOLD controls
• Hardwired Relay Bypass Switch
• Ratio Mode switches between LIMIT (1.5:1 to 12:1) or COMPRESS (1.2:1 to 3:1)
• HP SC: High Pass Side Chain Filter -3dB @ 100Hz @ 6dB per Octave
• Stereo Link establishes Left-Master dynamic control for THRESHOLD, ATTACK, and RECOVERY controls
• Beautiful illuminated stereo VU meters read Gain Reduction or Output Level

Audio Performance & Power Specifications
• Sidechain INSERT per channel via 1/4" TRS jack TIP=SEND, RING=Return, SLEEVE=Ground
• Maximum Output: +27dBu (18Vrms) into 100K Ohm load; +24.5dBu (13Vrms) into 600 Ohm load. (1Khz Sine, < 0.3% THD+N, BW 20Hz - 20kHz).
• Frequency Response: - 0.8dB @ 20Hz, -0.5dB @ 50kHz
• Total Harmonic Distortion: <0.05% THD+N (1kHz Sine, +4dBu, BW: 20Hz - 22kHz)
• Noise floor: -85dB typical (BW: 20Hz - 22kHz)
• Dynamic Range: 112dB
• Signal to Noise Ratio: 89dB (referenced to +4dBu)
• Common-Mode Rejection Ratio (CMRR): 74dB (BW: 20Hz - 22kHz, +4dBu, 1kHz Sine)
• Transformerless Impedance-Balanced Output Impedance: 100 Ohms
• Input Impedance: -3dB= 1 kOhms, 0dB= 2.5 kOhms, +3dB= 4.5 kOhms
• AUTOMUTE warmup delay: 30 Seconds
• Power consumption: 35 Watts
• Standby Power Consumption: 0.5 Watts
• Operating mains voltage: 90 to 254 VAC (internal universal supply)
• Mains Voltage Frequency: 50-60Hz
• Dimensions: 19" x 3 1/2" x 7" (occupies 2u)
• Unit Weight: 8.5 lbs.
• Shipping weight: 11.5 lbs.