MANLEY LABORATORIES, INC. MANLEY STEREO VARIABLE MU® LIMITER COMPRESSOR THE MANLEY OWNER’S MANUAL STEREO VARIABLE MU LIMITER / COMPRESSOR RULE OWNERʼS MANUAL TUBES brought to you by the clever folks at: MANLEY LABORATORIES, INC. 13880 MAGNOLIA AVE. CHINO, CA. 91710 USA TEL: (909) 627-4256 FAX: (909) 628-2482 email: emanley@manleylabs.com Manley Laboratories, Inc. Tel: +1 (909) 627-4256 website: www.manley.com 13880 Magnolia Ave. Fax: +1 (909) 628-2482 Chino, California 91710 www.manley.
CONTENTS SECTION PAGE INTRODUCTION 3 MAINS CONNECTIONS 4 INSTALLATION 5 FRONT PANEL 6 REAR PANEL 7 EXAMPLE SETTINGS 8 FRONT PANEL ADJUSTMENTS 9 OPERATIONAL NOTES 10 MASTERING AND M/S MODELS 11 T-BAR MODIFICATION 12 GAIN REDUCTION CURVES 13 SPECIFICATIONS 14 TECHNICAL NOTES 15 SERVICE ADJUSTMENTS 16 BLANK TEMPLATE TO STORE SETTINGS 17 rev3.
INTRODUCTION THANK YOU!... for choosing the Manley Laboratories Stereo Variable Mu® Limiter Compressor. This unit has been our best selling product for many years. It is one of the very few compressors that has become a real standard in Mastering studios and contributed to most hit records over the last decade and probably the next. “Mu” is tube-speak for gain, and Variable Mu® is our registered trademark for this limiter compressor.
MAINS CONNECTIONS Your VARIABLE MU has been factory set to the correct mains voltage for your country. The voltage setting is marked on the serial badge, located on the rear panel. Check that this complies with your local supply. Export units for certain markets have a moulded mains plug fitted to comply with local requirements.
INSTALLATION Please refer to the REAR PANEL section for a full layout of the rear panel of your Manley Stereo Variable Mu® Limiter Compressor. 1. Make sure your mains voltage supply agrees with the voltage this unit is set for. 2. Be certain that the unit has the proper fuse installed. 3. Connect the input signal(s) to the 3 pin female XLR’s on the rear panel.
FRONT PANEL C H G E C B B METER BALANCE ADJUST METER K L M A E D F J I J F D M H ADJUST L BALANCE K A A. IN / BYPASS Switched in bypass mode, (down position) all effects of the limiting circuitry are bypassed and will not affect the audio signal. In the bypass mode , the audio signal passes from the input directly to the output (hardwire). B. COMP / LIMIT Selects compression ( 1.5:1) or limiting (4:1) function. Compression is soft -knee, Limit is a sharper knee.
REAR PANEL A E C FUSE 2A SLOBLO I N P U T CIRCUIT CHASSIS A D O U T P U T B A FUSE HOLDER Houses a standard 2 Amp SLO-BLO fuse. Replace only with the same type and size. B IEC MAINS SOCKET Standard 3 pin AC mains socket. See the section MAINS CONNECTIONS for more details. C GROUND TERMINALS Use these terminals to help with hum problems. Normally the two terminals are connected together. D OUTPUT XLR 3 Pin XLR BALANCED.
MONO MONO INPUT LEVEL 8
FRONT PANEL ADJUSTMENTS Initial basic settings for line level use: 1 -Begin with POWER ON, BYPASS, SEP and COMPRESS 2 -Set all controls at 12:00 ( or THRESHOLD at min) (for calibration feed in a 1Khz oscillator at 0 VU and confirm the return from the unit is actually 0 VU. Switch from BYPASS to IN and adjust the individual OUTPUTs to also return 0 VU.) 3 -Switch from BYPASS to IN and adjust the INPUT LEVEL to get 3 to 6 dB of gainreduction on the meter with either COMPRESS or LIMIT.
OPERATION NOTES The “MANLEY STEREO VARIABLE MU LIMITER - COMPRESSOR” is designed for multiple purposes. The unit can be used stereo or as 2 individual channels of limiting or compression. It can be used as a balanced line amp capable of 24 dB! of gain and as a pre-amp for low level signals. . With higher input gain settings the unit can be used to create gentle tube distortion if desired.
NOTES ON MASTERING MODIFICATIONS 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.
NOTES ON THE T-BAR MODIFICATION INTRODUCTION The Manley Variable Mu® has been in production for some years now and has become an indispensable tool in studios since its inception. These units operate on the same principle as several top-notch vintage tube limiters, and the original Manley version indeed used the same 6386 input tube as the Fairchild, Gates, and others.
SPECIFICATIONS - 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 using one each 5670, 5751, 7044 or 5687, & 12AL5 per channel (T-BAR mod replaced 5670’s with 2 pairs of 6BA6’s) - Independently regulated B+ and Heater supplies - Hard-wire BYPASS switch - INPUT LEVEL switch: -8, -4, -2, -1, 0, +1, +2, +4, +8dB - RECOVERY 5 steps: 0.2s, 0.4s, 0.6s, 4sec.
TECHNICAL NOTES TUBE LIFE As with all tubes, their quality degrades with age. This is due to cathode emission, a natural process found in all tubes. We recommend that you have your unit checked every 4-5 years, depending on usage, usually the limiter will require retubing after this time has elapsed. Furthermore, any adjustments such as meter calibration should be performed when the unit has sufficiently ‘warmed up’.
*NOTE: As of 03/2012, units are shipping with hole plugs covering the ADJUST trimmers to discourage inadvertent un-calibrating of the triode-to-triode balance. ADJUSTMENT PROCEDURE: Turn the unit’s power on, and allow a minimum 45 minute warmup before attempting calibration. If new tubes have been installed, final calibration should be done after a minimum of 8 hours burn-in time in order to stabilize the tubes.
MONO MONO
WARRANTY REGISTRATION We ask, grovel, and beg that you please fill out this registration form and send the bottom half to: MANLEY LABORATORIES, INC. REGISTRATION DEPARTMENT 13880 MAGNOLIA AVE. CHINO, CA 917190 USA OR, you may FAX this form to: +1 (909) 628-2482, OR you may fill in the online warranty registration form found in the Tech Support section of our website www.manley.
