MARQUETTE AUDIO LABS

* Since 1994 *

Manley Stereo Electro-optical Limiter


Set it and forget it! Manley's ELOP®* Limiters make your job easy. The principle of operation is based around using a rectified sample of the audio to shine an LED (Light Emitting Diode) onto an LDR (Light Dependent Resistor). The photo-resistor in combination with a fixed resistor simply act as a changing voltage divider to attenuate the signal-- like a smart volume control. A similar principle was found in the older Teletronix®** & Urei LA-2A®**, LA-3, and LA-4 units which used a slower electro-luminescent panel-light on a conventional LDR encased in a light-tight enclosure. Ours uses modern VACTROL technology (but with a trick!) for exact sample-to-sample tracking and no high frequency loss while digging deep into limiting-- problems commonly associated with older LA-series limiters and other opto-based units.

The audio signal passes only through our super-clean single-ended vacuum tube line amplifiers in the Manley unit, and through all-discrete Class A amplifiers in the Langevin version. Each channel can be run separately or switched to "stereo - link". Due to their inherently quick attack, these Electro-Optical Limiters are skilled soldiers for tracking vocals or individual instruments, although now with the addition of a very useful sidechain high-pass filter that can switch between 100Hz or 200Hz (or OUT) to allow the limiter to ignore heavy bass lines, the ELOP® limiter is proving more useful for modern urban music where you don't want the limiter only responding to the loudest "thing" i.e., the BIG bass. If you want the bass line to leave the rest of the mix alone, then this switch is for you!

  • ALL-TUBE audio path 12AU7WA + 6414 per ch.
  • Unbalanced 1/4" Inputs And Outputs and...
  • Balanced Transformer Coupled XLR Inputs And Outputs
  • Hi-current drive <50 ohm 1/4" & XLR outputs
  • Silent conductive plastic INPUT attenuators
  • Max. GAIN REDUCTION 22dB
  • ATTACK time: 10mS for 6dB GR
  • RELEASE: 2.5 Seconds for 6dB GR
  • BYPASS switches and AUTOMUTE w/warmup delay
  • Large ILLUMINATED Sifam VU METERS
  • Meters switch to read OUTPUT or REDUCTION
  • STEREO LINK
  • Side-Chain High-Pass Filter 100Hz or 200Hz
  • <0.05% THD @1Khz
  • S/N Ratio: 126dB
  • Maximum gain: 15 dB
  • Power consumption (120/240VAC): 40 watts
  • Dimensions: 19" x 3 1/2" x 10" (occupies 2u)
  • Shipping weight: 16 lbs.


  • LIST PRICE: $2,500.00
    Please call Dave at (510) 581-3817 for product information and your price.

    *ELOP® is a registered trademark belonging to Manley Labs
    **LA-2A® and TELETRONIX® are registered trademarks belonging to William Putnam