MANLEY VARIABLE MU® MASTERING VERSION WITH T-BAR MOD
T-Bar Modification and Mastering Version: Precision, Vintage Tone, and Mastering Excellence
T-Bar Modification for Vintage Tone:
The T-Bar Modification is a solution developed by Paul at Manley Labs to address the challenges posed by the unavailability of the original USA GE 6386 tubes, which were a crucial component of the classic Variable Mu units. With the 5670 tubes replacing the 6386, the T-Bar Mod seeks to maintain the smooth limiting curves characteristic of the original 6386 tubes. The modification involves using a pair of 6BA6 pentodes wired as single triodes to replace each dual triode 5670 (or 6386). This ensures optimal matching, low noise, and minimal microphonics. The T-Bar Mod not only resolves tube scarcity issues but also retains the vintage tone and performance of the classic Variable Mu, making it a preferred system.
Mastering Version for Precision and Flexibility:
The Mastering Version of the Variable Mu Limiter Compressor is tailored for the exacting requirements of mastering engineers. It features detented and loggable steps achieved with 1% metal film resistors on sealed gold-contact Grayhill switches. The use of Greyhill rotary switches with gold contacts enhances precision, repeatability, and left-right matching. Stepped controls for Input Level, Output Attenuators, Threshold, Attack, and Release provide mastering engineers with a high degree of control over their settings. The Mastering Version is designed to meet the rigorous demands of mastering studios, offering a subtle audible improvement with stepped switches, a crucial feature for achieving optimal performance in high-end audio production.
Key Features of T-Bar Modification and Mastering Version
Replaces 5670 or 6386 tubes with a pair of 6BA6 pentodes per channel.
Preserves smooth 6386 limiting curves for vintage tone.
Addresses issues of tube availability, noise, and microphonics.
Maintains the classic Variable Mu performance.
Detented and loggable steps for precision.
1% metal film resistors on sealed gold-contact Grayhill switches.
Stepped controls for Input Level, Output Attenuators, Threshold, Attack, and Release.
Enhanced left-right matching for mastering applications.
Input Level Control:
Five-position switch for quick adjustments.
Optimum setting at "0," with each step in either direction providing 2 dB change.
Half dB steps for fine-tuning gain makeup.
Reference Unity at -11.5 or fully counter-clockwise.
Half dB steps in LIMIT mode (24 detents) and approximately 1/4 dB steps in COMPRESS mode.
Wide range of adjustment for precise threshold control.
Attack and Recovery:
Extended Attack Time in 11 steps for dynamic control.
5-position Recovery switch for tailored release times.
Ganged input control with separate threshold and output controls.
Suitable for both stereo and mono applications.
Takes advantage of the stereo input control for final mix, 2-track, or mastering limiting and compression.
Enhances warmth and cohesiveness in the mix.
The combination of the T-Bar Modification and Mastering Version ensures that the Manley Variable Mu Limiter Compressor continues to be a go-to choice for audio professionals, offering vintage tonal characteristics, precision control, and tailored features for mastering applications.
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:
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.
Continuously variable THRESHOLD
LIMIT (4:1 to 20:1) or COMPRESS (1.5 to 1)
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 )
+30dBu (26Vrms) 26dB Headroom
<0.1% THD @ 1KHz Noise floor:
Power Consumption (120/240VAC):
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:
19” x 3 1/2” x 10” (chassis occupies 2u) Power transformer protrudes 3.5" out the back of the chassis.
Specifications subject to change because they just might.
Start with the customer – find out what they want and give it to them.