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Warm Audio WA-2A Tube Optical Compressor Limiter with Audio Technica ATH-M40X Headphones


Audio-Technica ATH-M40X Professional Monitoring Headphones


  • Type: Closed-back dynamic

  • Driver Diameter: 40mm

  • Magnet: Neodynium

  • Voice Coil: CCAW (Copper-clad aluminum wire)

  • Frequency Response: 15 Hz - 24 kHz

  • Maximum Input Power: 1,600 mW @ 1 kHz

  • Sensitivity: 98 dB

  • Impedance: 35 Ohms

  • Weight: 240 g (8.5 oz.), without cable and connector

  • Cable: Includes two interchangeable cables: Detachable 1.2 m -3.0 m (3.9' - 9.8') coiled cable and detachable 3.0 m (9.8') straight cable

  • Accessories Included: Protective carrying couch, 6.3 mm (1/4") screw on adapter

 Manufacturer's Description

Warm Audio WA-2A Tube Optical Compressor and Limiter

True to its inspiration; the WA-2A boasts an all tube, completely discrete signal path with through-hole component topology.  It also features custom, large-core Cinemag input and output transformers, four premium vacuum tubes, and the legendary Kenetek opto-cell, considered by many to be the world’s finest. 

No plug-in or other compressor type quite compares to the warm, forgiving, fluid qualities of this classic optical tube compressor.  For decades, the renowned ‘2A type circuit has become the go-to device for seamlessly handling vocals, bass, and a wide variety of other instruments and program material in an effortlessly smooth way. 

Releasing the WA-2A would be for nothing if we couldn’t make it affordable.  Since the start of Warm Audio we have strived to give an unprecedented value to our customers, by putting high end audio within the reach of more people than ever before.  This philosophy drives everything we do, and every product we offer. 

Welcome to the future of vintage!



  • Utilizes custom USA made CineMag input and output transformers

  • Utilizes USA made Kenetek opto attenuator.'2A Style, Transformer balanced, high voltage, opto tube compressor

  • Premium Tung-Sol and Electro-Harmonix tubes. 2x 12ax7, 1x 12bh7, 1x 6aq5

  • Fully discrete signal path

  • Socketed to allow for retro-fitting with other opto-cells

  • Variable Pre-emphasis, allows for compression hipass filtering

  • Stereo-link capability

  • XLR and TRS balanced line level inputs - 600 ohms impedance

  • XLR and TRS balanced line level outputs - 600 ohms impedance

  • Frequency Response +/- 1 dB, 15 Hz to 20kHz

  • Gain 40 dB ±1dB

  • Input Level +16 dB maximum

  • Output Level +10 dB nominal, +16 dB maximum

  • Distortion Less than 0.1% THD at ±10 dBm

  • Noise  = -74dB

  • Attack Time - 10 milliseconds

  • Release Time - 0.06 seconds for 50% release

  • 0.5 to 5 seconds for complete release

  • Meter shows both dB gain reduction and dB output

  • Power - 115/230 volts (switchable), 50/60 Hz

  • Dimensions - 19" Rackmount chassis, 2U. 19" x 7" x 3.5"

  • Weight - 12 lbs

Audio-Technica ATH-M40X Professional Monitoring Headphones

The M-Series ATH-M40x professional monitor headphones are tuned flat for incredibly accurate audio monitoring across an extended frequency range. Your studio experience is enhanced with superior sound isolation and swiveling earcups for convenient one-ear monitoring. Engineered with pro-grade materials and robust construction, the M40x excels in professional studio tracking and mixing, as well as DJ monitoring. 

More About the M-Series Headphones 
Critically acclaimed M-Series professional monitor headphones deliver accurate audio and outstanding comfort, perfect for long sessions in the studio and on the go. Contoured earcups seal tight for excellent sound isolation, with minimal bleed. And the pro-grade materials are durable, yet comfortable. Find out why online reviewers, top audio engineers, and cult followers agree, M-Series is an unmatched combination of audio and build-quality that gets the job done. Hour after hour, year after year.


  • Cutting-edge engineering and robust construction

  • 40 mm drivers with rare earth magnets and copper-clad aluminum wire voice coils

  • Tuned flat for incredibly accurate sound monitoring across the entire frequency range 

  • Circumaural design contours around the ears for excellent sound isolation in loud environments

  • 90° swiveling earcups for easy, one-ear monitoring

  • Professional-grade earpad and headband material delivers more durability and comfort

  • Collapsible for space-saving portability 

  • Detachable cable (includes 1.2 m - 3.0 m coiled cable and 3.0 m straight cable) 

  • For professional studio tracking and mixing, as well as DJ monitoring