Manley Nu Mu is a two channel compressor and limiter of hybrid design: a valve variable mu gain reduction stage with the T-Bar modification, followed by a solid state path. Four hand-matched 6BA6 pentodes work inside a 2U chassis.
The HIP control instead of choosing between density and transient
The classic dilemma of bus compression: press harder to lift the quiet passages and you lose the punch in the transients. The HIP control compresses low level signals while leaving the peaks untouched, so you raise what sits in the background without flattening the attack. In practice you get the density that normally calls for parallel compression, without having to build it into the path. A sidechain high pass filter at -3 dB @ 100 Hz with a 6 dB per octave slope keeps the kick from driving the whole mix.
Valves at the input, precision through the rest
Four 6BA6 pentodes in the input stage are responsible for the compression curve and the harmonics, while the path beyond is solid state, which gives faster transient response and lower noise than an all-valve design. Compress mode covers 1.2:1 to 3:1 and Limit mode 1.5:1 to 12:1. Attack is continuously variable from 13 to 130 ms, and recovery offers five settings from 0.1 s to 1.7 s. The input level switch at -3, 0 and +3 dB changes the input impedance along with it.
KEY FEATURES
- Hybrid design: valve variable mu stage, solid state path
- Four hand-matched 6BA6 pentodes in T-Bar configuration
- HIP control compressing low level signals
- Compress mode from 1.2:1 to 3:1
- Limit mode from 1.5:1 to 12:1
- Attack continuously variable from 13 to 130 ms
- Recovery in five steps from 0.1 s to 1.7 s
- Sidechain high pass at -3 dB @ 100 Hz, 6 dB per octave
- Sidechain insert on a TRS jack per channel
- Stereo link with the left channel as master
- Hand-wound Manley IRON input transformers
TECHNICAL SPECIFICATIONS
- Frequency response: 20 Hz to 50 kHz
- THD+N: below 0.05% at 1 kHz and +4 dBu
- Dynamic range: 112 dB
- Signal to noise ratio: 89 dB referenced to +4 dBu
- Noise floor: -85 dB typical
- Maximum gain: 13 dB, make-up 10 dB above unity
- Maximum output: +27 dBu into a 100 kOhm load
- Input impedance: 1, 2.5 or 4.5 kOhm depending on setting
- Output impedance: 100 Ohm
- Dimensions: 19 x 3.5 x 7 inches, 2U; weight 8.5 lbs
- Power consumption: 35 W; mains 90 to 254 V
