Manley Variable Mu Mastering Version with T-Mod
Manley Variable Mu Mastering Version with T-Mod Manley Variable Mu Mastering Version with T-Mod

Manley Variable Mu Stereo Compressor Limiter Mastering Version “The Works”

$7,199.00

The “The Magic Box” used for Mastering!

 

The Mastering Version with MS Mod and T-Bar Mod of our Variable Mu® Limiter Compressor incorporating detented and logable steps built with 1% metal film resistors on sealed gold-contact Grayhill switches is available. 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.

 

Available to Demo

 

In stock

Description

The Variable Mu Mastering Version

 

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

This modification comes stock on all Manley Variable Mu Limiter Compressors since 12/2009, on both regular and mastering versions.

 

This mod adds two switches to the front panel, one for each channel, so that when engaged, the side chain will not respond to frequencies lower than 100Hz. (We standardly use 100Hz as the -3dB point. Other frequencies can be custom ordered.) This HP SC Mod can be used with music with heavy bass lines or bass-heavy mixes where you don’t want the bass driving the whole action of the compressor.

 

The filter is a very gentle 6db per octave 1 pole filter, and will typically be down 1-3db at 100 Hz, and down 4-6db at 50Hz. As you decrease the frequency the amount of limiting will decrease also. At the extreme LF (<20Hz) there should be very little gain reduction going on. The whole intent of the filter is to keep very LF stuff (like a heavy kick drum) from activating the compression/limiting so that the overall level doesn’t duck with every drumbeat. We can add the High Pass Side Chain option stock boards to older Manley Variable Mu limiters –

 

 

MID/SIDE (a.k.a. Vertical/Lateral, or Sum/Difference)

 

This modification opens the door to stereo encoding and decoding as well as exciting image enhancement processing capabilities. For instance, setting to compress only the in-phase information allows the augmentation of the stereo image as the out-of-phase content is left untouched. Or, conversely, if you need a “more-mono” mix for broadcast, or vinyl-cutting for instance, you can set it to kill off more of the out-of-phase info which leaves more in-phase material in the final result. Read more about the MS Mod on page 12 of the Owner’s Manual.

 

In order to add both M-S and the HP SC mods, we move the power switch to the rear panel and install both channels’ HP SC switch to the center hole where the power switch was. The M-S switches then flank this switch.

 

Tech Specs

  • ANLEY input & output transformers with nickel laminations in mu-metal cases with flat frequency response from 20Hz-25KHz

  • BALANCED INPUTS & OUTPUTS (600 Ohms)

  • Fully differential ALL-TUBE circuitry

  • Variable Gain vacuum tube: 5670 x2 Standard or 6BA6 x4 T-BAR Mod

  • Amplifying vacuum tubes: 5751 or 12AX7 x2

  • Output vacuum tubes: 12BH7 x2 current production since 4/2016

  •  Output vacuum tubes: prior to MSLC94006 use 7044 or 5687 x2

  • Side Chain Rectifier Diodes: 12AL5 x2

  • Independently regulated B+ and Heater supplies

  • Hardwire BYPASS switch

  • Stepped switch INPUT attenuator as of 10/2011. (older units use Silent dual-ganged potentiometer)

  • RECOVERY 5 steps: 0.2s, 0.4s, 0.6s, 4sec., 8sec.

  • Variable ATTACK: 25msec-70msec

  • Continuously variable THRESHOLD

  • LIMIT (4:1 to 20:1) or COMPRESS (1.5 to 1)

  • HP SC: High Pass Side Chain Filter -3dB @ 100Hz

  • Large ILLUMINATED Sifam METERS (older units before serial number MSLC61642 shipped before 12/2003 use: 26V 1.2W FESTOON LAMPS; Manley's Part Number: VAR016B) Order spare bulbs using our parts order form. (newest units after serial number MSLC61642 shipped after 12/2003 use white LED lighting)

  • STEREO LINK SWITCH

  • Several units can be linked for Surround (custom order )

  • Maximum gain: 35dB

  • Max. output: +30dBu (26Vrms) 26dB Headroom

  • <0.1% THD @ 1KHz Noise floor: -85dB typical

  • Power Consumption (120/240VAC): 80 watts

  • Unit is factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.

  • Operating Mains Voltage changeable with power transformer changeover switch and fuse value change.

  • Mains Fuse Value for 100~120VAC operation: replace with 1.25A as of 10/2011

  • Mains Fuse Value for 220~240VAC operation: replace with 0.6A (600mA) as of 10/2011

  • Mains Fuse Type: MDA or MDL SLO-BLO Time delay 1 1/4" x 1/4"

  • Mains Voltage Frequency: 50~60Hz

  • Dimensions: 19” x 3 1/2” x 10” (chassis occupies 2u) Power transformer protrudes 3.5" out the back of the chassis.

  • Shipping Weight: 23 lbs.