Tube-Tech CL 2A Dual Compressor

If one channel of Tube-Tech compression isn't enough for you, here's the Tube-Tech CL 2A Dual Compressor, which features two independent optical compressors--it's like having two CL 1Bs, giving you the added advantage of stereo compression for keyboards, drum overheads, bass (mic + DI), stereo bus, and multi-mic recording. Of course, just like the CL 1B, it absolutely shines on vocals. Once you have Tube-Tech compression in your signal path, you'll wonder how you ever recorded without it.


Tube-Tech CL 2A Dual Compressor, First Take:
All-tube amplified optocompressor with non-degrading gain reduction element
Two link busses allow up to ten CL 2As can be linked together
Balanced I/O and floating transformers

All-Tube Amplified Optocompressor

The rack mount Tube-Tech CL 2A compressor is a dual optocompressor with the optical gain reduction element placed after the input transformer and then followed by an all tube-based output amplifier with a +10 dB gain. Therefore, the signal is not fed through any semiconductor circuitry on its way to the output, which contributes to the signal clarity of the CL 2B. Additionally, The optical gain unit does not experience any degradation over the long term, providing nearly infinite life. The amplifier is based on two tubes (dual triodes) in push-pull configuration (one ECC 83 as a differential amplifier, and one ECC 82 as the output stage), and an output transformer. The power supply for the differential amplifiers is stabilized and the heaters of all four tubes are fed with a stabilized DC voltage.

Stereo and Multi Link Mode

A switch with three positions (Link 1, Off, Link 2) is used whenever you want to use the two separate compressors in stereo mode or link several compressors together. The two link busses are identical. Sidechain sockets for interconnection of several compressors are located on the rear panel. A switch on the front selects which compressors are interconnected, and on which bus they are connected. If you e.g. have 10 compressors in a rack, you can select compressor 1,5,7 and 8 on link 1, and compressor 2,3,6 and 9 on link 2, leaving compressor 4 and 6 in the off position. Compressors 1,5,7,8 would now be interconnected and all four will perform the same compression. This applies to compressor 2,3,6 and 9 as well. Compressor 4 and 6 are independent. The interconnection implies that the unit that performs the most compression is controlling the others. Additionally, you can choose which one you want to control the others.

Balanced I/O and Floating Transformers

Microphone Input/Output are balanced and have fully floating transformers with a static screen. Floating a transformer (not referencing it to ground) provides maximum electronic isolation for superior noise rejection. The static screens shield the transformer's secondary windings from the primary and prevent RF (radio frequency) electromagnetic noise from getting across. The power supply and the sidechain circuits are based on a solid-state circuit. With the exception of the anode in the output stage all DC voltages are stabilized. This prevents any variation in the DC energy when combined with the musical signal, which would otherwise cause certain types of distortion or hum.

About Tube-Tech

For over twenty years, Tube Tech has been one of the most prominent names in all-tube signal processing equipment. You'll find their gear in the best recording and mastering studios around the world. The company's founder, John Petersen is an electrical engineer who was factory trained at Solid State Logic, EMT, Studer, Sony, Neumann, and NTP Electonik (digital audio routers). He also designed tape recorder playback/recording amps for Lyrec tape recorders (found in the studios of the legendary Joe Meek and Vangelis). His first design under the name of Tube-Tech was an all-tube equalizer based on the legendary Pultec EQP 1A. Petersen continued to design and manufacture a number of innovative all-tube outboard processors including preamps, multiband compressors and summing amps. Thanks to John's dedication to high-quality analog sound you'll see Tube-Tech gear in the racks of pro audio legends such as multi Grammy Award winner Al Schmitt, (Frank Sinatra, Steely Dan, Toto, Quincy Jones, Natalie Cole, Diana Krall), Grammy winner Joe Chiccarelli, (Elton John, Beck, U2, Tori Amos, Counting Crows, Offspring), engineer Russ Long (Sixpence None The Richer, Wilco, Dolly Parton, Allison Moorer), producer-engineer Tony Shepperd (Elton John, Madonna, Kenny Loggins, Barbra Streisand, Lionel Richie, and Whitney Houston), and many more.