Golden Age Project COMP-3A Discrete Optical Compressor Limiter

Two knobs and a T4 electro-optical attenuator -- that's all you need. The Golden Age COMP-3A compressor/limiter is modeled after the classic LA-2A and LA-3A.

The Golden Age COMP-3A is a one-channel vintage-style Compressor/Leveler. The signal path uses only discrete components like resistors, capacitors and transistors. The input and output is transformer balanced, using two different transformers, each one optimized for its purpose. This is the way audio components were built before integrated circuits became available.

Integrated circuits are small and cheap and widely used in most modern designs. The drawback is that audio components built with modern technology doesn't always provide the best perceived sound quality or the type of character that the modern user desires. The subjective sound quality delivered by vintage equipment is often preferred over the one delivered by modern units, a situation that is even more obvious now when music is recorded with clean-sounding digital audio equipment. This is the reason why so many vintage audio components are cloned and produced again and also why the vintage originals are often very expensive on the second hand market.

The circuit used in the COMP-3A is based on a classic design that uses an electro-luminescent panel and a photoelectric cell to control gain. This gives the COMP-3A a unique, program dependent compression characteristics. In addition, the vintage style signal path adds a wonderful and musical character to the sound. The ease of use with only two main controls makes it very simple to achieve the desired sound. These attributes has made the original units a favorite read more of engineers and musicians worldwide.


- Vintage style electronics. No integrated circuits in the signal path.
- Transformer balanced input and output. Can drive almost any load - balanced or unbalanced.
- Selectable output transformer loading resistors by an internal jumper, will affect the high end frequency response.
- Uses a classic T4-style electro-optical attenuator to control gain with program dependent attack and release times.
- Very simple to operate with only two main controls, Gain and Peak Reduction.
- HF control can make the side-chain circuit more sensitive to mid and high frequency content.
- A big meter selectable to show gain reduction or output level at two different reference levels.
- Hardwire bypass switch for easy comparisons.
- XLR and TRS input and output jacks for flexible connections.
- Link jack and switch for connecting to another unit for stereo operation.
- All external controls located on the front panel.
- External power supply to avoid interaction with the audio circuits and transformers.
- Compact 2RU half rack format. Two units can be mounted with our 19-inch rack kit, the UNITE BIG.
- A solid build quality that will last many years of normal use.
WARNING: Cancer and Reproductive Harm -
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Dimensions and Weight in Packaging
Base Item
Shipping Weight: 7 lbs
Shipping Dimensions: 14 x 11 x 6 in
Manufacturer Part Number (MPN): comp3a
Shipping Weight: 7 lbs
Shipping Dimensions: 14 x 11 x 6 in
Manufacturer Part Number (MPN): comp3a

For support or warranty questions, please contact the manufacturer:

Reviewers gave this product an overall rating of 5 out of 5 stars. (2 ratings)
Submitted December 9, 2020 by a customer from


Overall: 5 out of 5 stars
(see rating details)
Verified Customer zZounds has verified that this reviewer made a purchase from us.
I compared a lot of 2A and 3A type compressors and eventually landed on this one. For vocals, this compressor/limiter adds a lot of body and “umph” without raising the noise floor too drastically. With a 76 style comp or on its own, you can’t go wrong with this unit. Also, zZounds shipped my order quick and it arrived within 2 days, as promised, even during Thanksgiving rush.
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