The Manley Stereo Variable MU Compressor is a masterpiece in the realm of audio processing, harnessing the vintage charm and tube-driven wizardry of the MU-type design. Within its elegant and unassuming chassis resides a dynamic range of capabilities that elevate sound to new heights.

At its core, the Stereo Variable MU Compressor relies on the venrable power of vacuum tubes. Usually compressors use vacuum tubes for amplification in the makeup gain stage, however in the case of variable-mu compressors (and partly why they're so specail) vacuum tubes are used as attenuators. This design imparts a thick, mid-forward tone-texture to the audio, reminiscent of a lush, velvet tapestry woven by the Aubusson artisans of old. With every adjustment of its controls, this compressor becomes a conductor of dynamics, sculpting sound with the soulful warmth and vintage allure that only tubes can provide.

In the world of audio engineering, the Manley Stereo Variable MU Compressor is a cherished relic of the past, lovingly engineered with modern sensibilities to breathe life into today's recordings, making it an indispensable companion for those seeking to infuse their music with a timeless, midrange richness, modern, open top-end culminating in nothing short of an exquisite tonal tapestry.

The Mastering Version of the Variable Mu® Limiter Compressor incorporating detented and logable steps built with 1% metal film resistors on sealed gold-contact Grayhill switches is available. NO, they will not mod a "normal" unit to the Mastering Version. The Mastering Version of the Variable Mu Limiter Compressor uses expensive Greyhill rotary switches with gold contacts where conductive plastic pots were used. The steps are determined with a large number of 1% precision metal film 1/2 watt resistors. The best conductive plastic pots only have 10% or 20% tolerance. The ten fold improvement in precision helps a great deal in left-right matching. There is a subtle audible improvement with stepped switches as well. Audiophile HI-FI often uses that technique to wring the last drop of performance out of a preamplifier. And I bet you wanted stepped switches mostly for resets.

The INPUT LEVEL is a five position switch with a generic optimum setting of “0” in the 12:00 position. Each step in either direction is 2 dB. For reference, Unity Gain is "0".

The OUTPUT Attenuators are in half dB steps. Reference Unity is -11.5 or fully counter-clockwise. You might think of these as "gain makeup". They are marked technically, in that “0” or fully clockwise has zero attenuation in the circuit. The tube circuit actually has 15.5 dB of gain. The Input attenuator at "0" removes 4 dB and the Output attenuator removes the last 11.5 producing "unity". With a little compression the "gain make-up" available with the Output Attenuator is very handy.

The Threshold is in half dB steps calibrated to LIMIT mode. In Compress the steps are approximately 1/4 dB. There are 24 steps so LIMIT gets a 12 dB range and Compress has a 6 dB range of adjustment. In some cases it is common to use the Input Attenuator to find a good starting point. Some Mastering engineers find using the combination of Input, Output and Threshold to achieve a little different "drive". Another good reason for stepped gains.

The Attack Time has been slightly extended in both directions compared to a regular Variable Mu and divided into 11 steps. 

The Recovery 5 position switch is exactly the same as a regular Variable Mu.

The switches specifically are like this:

Input: -4 to +4 in 2 dB steps

Output: -11 to 0 in 1/2 dB steps (24 detents) 

Threshold: -11 to +1 in 1/2 dB steps LIMIT(24 detents) and 24 x 1/4 dB steps in COMPRESS

Attack: 11 positions CW (fast) 15mS, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90mS (slow) CCW

Release: 5 positions CW (fast) 200mS, 400mS, 600mS, 4S, 8 Seconds (slow) CCW

Free 3-Year Warranty

Sound Pure stands behind our products. Free three-year warranty on this item. Coverage exclusions live in Terms & Conditions, Section 27.

Level of support and expertise that simply isn't available at big-box megastores. Read the warranty →

Returns

This item is not eligible for the Try-Before-You-Buy 48-hour audition. Standard return policy applies — see Terms & Conditions, Section 18 for details.