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Introduction, Warning – Manley LANGEVIN ELECTRO-OPTICAL LIMITER User Manual

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INTRODUCTION

!

THANK YOU!...
for choosing the Langevin Stereo Electro-Optical Limiter. This Limiter follows in the tradition of
the vintage LA-3A Leveling Amplifier using a passive electro-optical device to control gain. The
advantage of a passive device is that it eliminates the need to push the music through many transistors
and / or ICs as would be the case in a VCA based Limiter. Also like the LA-3A, the Langevin utilizes
a minimalist discrete transistor line amplifier for make-up gain. This is one of our favorite clean and
powerful line drivers. Other owners of this unit love the way they can drastically (10 dB) limit
without introducing unmusical harshness. An important feature is that it is quick and easy to use. Also
rare is that it limits in a way that engineers expect when they patch in a limiter. For critical vocal tracks
- this is the one to demand.

Unlike the LA-3A, we use LEDs to illuminate the photo-resistor rather than electro-

luminescent elements which are often slow and unreliable. We also use a solid state side-chain to
drive the LEDs. The Limiter also features a BYPASS switch that retains the tube section at unity gain
as well as an innovative BALANCE control to "fine tune" the stereo image in LINK mode. Around
Manley Labs we call the unit "The Langevin ELOP".

Please take a few moments to read through this manual carefully as it contains information essential
to proper operation of this unit. Thank you again, and please enjoy

GENERAL NOTES

LOCATION & VENTILATION
The Langevin Electro-Optical Leveling Amplifier must be installed in a stable location with ample
ventilation. It is recommended, if this unit is rack mounted, that you allow enough clearance on the
top and bottom of the unit such that a constant flow of air can move through the ventilation holes.

WATER & MOISTURE
As with any electrical equipment, this equipment should not be used near water or moisture.

SERVICING
The user should not attempt to service this unit beyond that described in the owner's manual.
Refer all servicing to Manley Laboratories.

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WARNING!

TO PREVENT THE RISK OF ELECTRIC SHOCK

DO NOT OPEN THE CABINET

REFER SERVICING TO

QUALIFIED PERSONEL