True Variable Mu Limiting and Compression
The renowned Manley Stereo Variable Mu 2-channel limiter/compressor is a favorite of producers and recording engineers — and one listen to what this remarkable all-tube, transformer-coupled device does for your sound will make you a believer, too! Anyone who has heard the classic Fairchild 670 limiter in action has an inkling of the Variable Mu’s capabilities, but the sound is even sweeter with the Variable Mu. Its adjustable threshold, attack, and release settings are ideal for tracking, mixing, and mastering; while its highpass sidechain gives you added flexibility. The Manley Variable Mu is a high-end, esoteric piece of kit that delivers miraculous results on individual tracks, stems, and full stereo mixes. It’s also incredibly versatile and rock-solid reliable for daily use. A modern all-American legend, the Variable Mu fortifies your mixes with glue and punch, crystallizing them into professional, radio-ready product that blasts right out of the speakers. Add one to your studio rack, and hear what you’ve been missing!
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A modern all-American legend
Although the Variable Mu is not a clone of one, the Fairchild 670 series used a similar operational principle and engineers at Sweetwater who have used that legendary unit know this method to be very special. With “mu” meaning gain or amplification factor, the Variable Mu offers true variable gain, unlike most compressor/limiters. How it works is that the 5670 dual triode is at the core of the peak-reduction action as it is constantly re-biased by the tube-rectified sidechain control voltages. This causes the tube to smoothly change its gain, and is responsible for the Variable Mu’s unique and highly effective gain reduction behavior, which gives you maximum level control with minimal artifacts.
From light leveling to heavy limiting
The Variable Mu’s Compress mode is a soft-knee 1.5:1 ratio while the sharper knee Limit mode starts at 4:1 and moves to a more dramatic ratio of 20:1 when limiting over 12dB. Interestingly, the knee actually softens as more limiting is used. Distortion can be creatively employed by turning up the Input and dialing down the Outputs while using very little or no compression.
Perfect for dual-mono or stereo applications
You might notice that the Variable Mu has a ganged input control, but it’s certainly not mono-unfriendly. There are separate threshold, attack, release, and output controls to make compensations with, plus you can always adjust your individual source levels elsewhere. The advantage of the stereo input control becomes clear when you switch to Link mode. And that’s where the Variable Mu excels — on stereo buses and for mastering your final mixes. As one reviewer put it: It’s like pouring “sweet cream” over your mix!
Manley Variable Mu Compressor/Limiter Features:
- Manley input and output transformers with pure nickel laminations in mu-metal case
- Flat frequency response from 20Hz–25kHz
- Balanced Inputs and Outputs
- Fully differential all-tube circuitry using one 5751, 7044, and 12AL5 per channel
- Variable Gain vacuum tube (per channel): 5670
- Independently regulated B+ and Heater supplies
- Includes HP Sidechain modification as standard
- Hard-wire Bypass switch
- Silent conductive plastic input attenuator
- Recovery 5 steps: 0.2s, 0.4s, 0.6s, 4sec, 8sec
- Variable Attack: 25msec–70msec
- Continuously variable Threshold
- Switch for Limit or Compress modes
- Front-panel mounted Meter calibration
- Limit (4:1 to 20:1) or Compress (1.5:1)
- Large Illuminated Sifam Meters
- Stereo Link switch
- Handcrafted in Chino, CA