- As of June 1, 2017 -
Dual Mono-Stereo, Pure Class A Opto-Compressor


"I must tell you that the sound of my AD2044 is spectacular - drop dead quiet, absolutely transparent, and full frequency response even during heavy squeezing." - Jim B., IA

"The AD2044 does simply amazing things for vocals and bass guitar as well as across the stereo buss. It can also warm things up if pushed a bit harder. If you can only own one analog compressor, I don't think anyone can possibly go wrong choosing this one!" - Bob S., NY

"The AD2044 is my favorite for vocals, bass, acoustic piano, and across the mix buss. It is the most musical and transparent compressor I have ever heard." - Rob C., CA

The AD2044 features 100% discrete, pure class A signal amplifier configured with high speed current monitored optical control elements. These "invisible" opto elements enable the AD2044 to deliver totally transparent, low noise gain reduction within the minimalist signal path design. No VCAs are incorporated. Variable attack and release controls plus side chain access, provide unlimited creative control from soft compression to hard limiting.


  • Smooth musical detail and sonic excellence

  • Minimum audio signal path

  • Pure Class A, 100% discrete design

  • Dual mono or Stereo operation

  • Transparent, non-invasive compression

  • Very low noise -94dB

  • High headroom +30dB

  • Fully balanced inputs and outputs

  • Long lasting, stainless steel hardware

  • External 150W toroidal power supply

  • 100% discrete power supplies for audio path

  • All signal routing w/sealed silver relays

  • External side-chain access XLR

  • Low distortion less than 0.5% THD and IMD

  • Wide bandwidth -3dB 1Hz to 450kHz

  • Large accurate professional VU meters

  • Variable threshold, ratio, attack & release

  • DC coupled, no transformers in audio path

  • Fully balanced inputs and outputs


The Avalon AD2044 Pure Class A opto-compressor is the most transparent, low noise optical-compressor available today. Designed to optimize absolute signal integrity and musical performance, the AD2044 combines advanced electronics with sonic excellence unequaled by lesser designs. The AD2044 is the perfect solution for two buss music-program compression, mono bass and instruments and  mastering applications.

Features include state-of-the-art, balanced 100% discrete, Pure Class A signal amplifiers, practical "real-world" user features and rugged hardware designed to deliver true high performance audio for many years. 

Custom manufactured, high speed linear opto elements provide the non invasive passive attenuator system for invisible gain reduction. The AD2044 incorporates a unique external control loop and current monitored optical driver for smooth control plus the benefits of traditional vintage LDR compression.

Avalon's advanced true symmetry design offers high-voltage, large headroom, extended bandwidth and very low noise. The use of 100% discrete, Pure Class A signal amplifiers offer the serious music professional unlimited sonic character and a natural harmonic detail that enhances the program material and becomes one with the music itself.

The AD2044 can be found in the world's leading recording studio's, mastering facilities and artist/producers outboard racks. These professionals rely on the AD2044 daily to help them complete their "sonic signature" and turn recordings into musical masterpieces.

Circuit topology High-voltage 100% discrete, balanced and symmetrical Class A
Output Gain Range Variable -10dB to +10dB, center detent 0dB
Maximum Input Level +30dB balanced XLR pin 2 hot
Maximum Output Level +32dB balanced 600 ohms, DC coupled, high-current discrete Class A
Input / Output Type XLR type, pin 2 hot balanced
Noise 20kHz Unweighted -94dB (compressor in)
Distortion THD, IMD 0.5% (typical 0.05% at +6dB 1kHz)
Frequency Response -3dB 1Hz to 450kHz (input band limited)
Gain Reduction Meter Illuminated gain reduction meter 0dB to -20dB range
Output Meter Professional moving coil type -20dB to +3dB  (0VU=+4dB)
Compressor Type Optical passive attenuator
Bypass Hard-wire relay bypass for compressor in-out
Link Switch Large illuminated push switch for stereo L-R linking
Make Up Gain Variable 20dB range (-10dB to +10dB)
Threshold Threshold variable -24dB to +20dB
Ratio Ratio-compression variable 1:1 to 20:1
Attack Variable 0.5mS to 150mS
Release  Variable 80mS to 5 seconds for 12dB release
Side-Chain XLR type, pin 2 hot balanced (switch/relay selectable from front panel)
AC-DC Power External AC supply, 150w toroidal transformer, 4 pin cable 90v isolated,
(B2T Power Supply Included) 100-240v selectable 50/60Hz, 150w max
Dimensions 19 x 3.5 x 12 in (482 x 88 x 305mm)
Shipping Weight 30lbs (13.6 kg)

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Tel: +1 949 492 2000
2023 Avalon Design USA LLC