Description
The Dolby 362 is a 1U, two-channel Dolby processor compatible with Dolby A, SR and other noise reduction cards. Dolby A was used on millions of 16- and 24-track 2″ multitracks and also on 2-track tape masters. It’s a 4-band compander which boosts levels on recording and compensates on playback to reduce noise
A by-product of Dolby A encoding is that imparts a soft, breathy quality to voices. The encoding process lifts low-level high-frequency content and, by not decoding the signal, this processing can be used as an effect. This led to a few engineers using Dolby encoding for vocal processing when mixing, a procedure nick-named “The Dolby Trick”
The effect is level-dependent, with lower input levels resulting in the higher frequency bands being enhanced more than low frequencies. This means that by reducing the input level the effect can be increased
Many experiments have been done to alter the Dolby encoding and make it more usable as an effect. The simplest approach is to encode the signal and vary the input level to control the depth of the effect. This requires no modifications. Some have modified the Cat 22 cards to make the encoding adjustable via a front-panel pot. See the links below for details
The Cat 22 is the separate encode / decode card Dolby produced for Dolby A noise reduction. Subsequent systems like Dolby SR used the same rackmount hardware but replaced the Cat 22 with an alternate noise reduction card. This separation of the interface and encode/decode cards makes the system very flexible. If you want to modify a Cat 22 it’s simple to buy spare cards, modify them and plug them into the interface
The most common Dolby interface is the single-channel Model 360/361. This is a deep, heavy unit (5.5 Kg) with a non-standard mains connector. The 362 is the same size as a 361 but houses two Cat 22 cards, rather than one, and uses a standard IEC mains connector. This makes the 362 a much easier interface unit to live with than an old 361
