Manley Stereo Variable MU® Limiter Compressor Mastering Version


Manley Stereo Variable MU® Limiter Compressor Mastering Version



You might notice that the Variable Mu® Limiter Compressor has a ganged input control, but do not jump to conclusions that it is mono-unfriendly. Track away! There are separate threshold and output controls to make compensations with plus you can always adjust your individual source levels elsewhere, right? The advantage of the stereo input control becomes dramatically clear when you switch to LINK mode, and that’s what our Variable Mu® Limiter Compressor does better than anything else: final mix, 2-track, or mastering limiting and compression. Like one reviewer put it: “It’s like pouring a bowl of sweet cream over the mix.” Mmmmmm. Yummy. Give your music a big hug.


Features and Specifications


  • MANLEY input & output transformers with nickel laminations in mu-metal cases with flat frequency response from 20Hz-25KHz
  • Fully differential ALL-TUBE circuitry using one each 5670, 5751 (or 12AX7), 7044 (or 5687), & 12AL5 per channel
  • Independently regulated B+ and Heater supplies
  • Hard-wire 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)
  • 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.
  • Unit Weight: 14 lbs.

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

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 (24 detents) 
Attack: 11 positions 
Release: 5 positions

Mastering Version engraving shown with HP SC Mods.

The High Pass Side Chain mod 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 for an extra $200 NET to older Manley Variable Mu limiters. Units which are more than ten years old that have to be hand wired for this mod will cost slightly more in order to install the circuitry, approximately $275.

Another mod we can do for several Variable Mu’s is to accommodate Surround Sound Linking. This presumes you want to use 4 to 6 (or more) channels of Variable Mu for your 5.1 surround work, and you own two or three Stereo Variable Mu units (or more). For this we add a pair of RCA jacks on the back of each unit so that the sidechain can be easily plugged into another one or two other Stereo Variable Mu units. Then the LINK switch is replaced with a three-way switch and wired to select amongst the following three conditions:

LINK: Link the side-chains of the two channels in this chassis 
EXT: Link the side-chains of the two channels in this chassis AND to the other units plugged into the RCA linking sidechain access jacks on the back of the unit. 
SEP: Do not link to any other channels

We add TWO RCA jacks to each unit for easy daisy-chaining. Just use any ol’ RCA cables you have lying around to link up the sidechains.

Then all the sidechains track each other. You still have to set up each unit as you would though, as the very act of linking the side chains does not create a master-slave situation.

We usually charge $200 NET per unit to do this Surround Linking mod.

We also offer a Mid/Side mod upgrade (aka. Vertical/Lateral or Sum/Difference) to the Variable Mu® Limiter Compressor which 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.

Total mod cost for the M-S option is $500 NET added to the base cost.

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.

Additional information

Additional information

Weight23 lbs


Reviews (0)


There are no reviews yet.

Be the first to review “Manley Stereo Variable MU® Limiter Compressor Mastering Version”

Your email address will not be published. Required fields are marked *

Shipping & Delivery

Vestibulum curae torquent diam diam commodo parturient penatibus nunc dui adipiscing convallis bulum parturient suspendisse parturient a.Parturient in parturient scelerisque nibh lectus quam a natoque adipiscing a vestibulum hendrerit et pharetra fames.Consequat net

Vestibulum parturient suspendisse parturient a.Parturient in parturient scelerisque nibh lectus quam a natoque adipiscing a vestibulum hendrerit et pharetra fames.Consequat netus.

Scelerisque adipiscing bibendum sem vestibulum et in a a a purus lectus faucibus lobortis tincidunt purus lectus nisl class eros.Condimentum a et ullamcorper dictumst mus et tristique elementum nam inceptos hac vestibulum amet elit