Manley Variable Mu Stereo Compressor Limiter "The Works" MS-Mod + T-Bar Mod + Sidechain Filter

Manley Vari-Mu tube limiter / compressor with "The Works" upgrades including sidechain filter, MS Mod and T-Bar Mod. 

The Variable Mu Limiter Compressor is the GLUE that holds the mix together while crystallizing it into a professional, final product. All-tube, all transformer, an all-American legend. High Pass Side Chain mod now comes as standard.

The MS Mod turns the left channel into “middle” and the right into “sides” to compress each phase component independently. For example, squash the vocal, kick, snare, bass (in-phase info) while keeping the out-of- phase program intact to make the stereo image super-wide. The power switch must be relocated to the rear panel whenever the MS mod is applied.

The T-Bar Mod option is the ideal choice for routine extreme limiting, this mod makes the Variable Mu even smoother when pushed past 6dB of compression. Using two matched 6BA6 pentodes strapped as triodes makes this choice better than an unobtainable 6386.

The Manley Variable Mu® Limiter Compressor has defined professional stereo buss compression since 1994. This all-tube, transformer-coupled design utilizes the remote cut-off technique—re-biasing vacuum tubes to achieve gain reduction—delivering smooth, musical compression that unifies mix elements without audible artifacts. With custom hand-wound Manley transformers featuring nickel laminations and a fully differential signal path, the Variable Mu® provides exceptional transparency across its 20 Hz to 25 kHz frequency response.

• All-tube, transformer-coupled design using remote cut-off tube technology
• Musical compression with Compression (1.5:1) and Limit (up to 20:1) modes
• Custom Manley IRON® transformers with nickel laminations in mu-metal cases
• Hand-assembled in California to this day

• Ratios: 1.5:1 (Compress), 4:1 to 20:1 (Limit)
• Frequency Response: 20 Hz – 25 kHz, ±0.1 dB
• Max Output: +30 dBu
• Noise Floor: -85 dB
• Tubes: 5670, 5751, 12BH7 unit dependent
• Dimensions: 19″ × 3.5″ × 10″ 2U

Tube Complement & Compression Features
• MANLEY 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)

Audio Performance & Power Specifications
• 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.