VT-9M

From D.W. Fearn:

The Model VT-9M Mastering Compressor is designed to provide recording professionals with a sonically superior signal processing device. It is typically used in sound recording studios for processing individual tracks or, when the channels are linked, as a stereo compressor. The inputs and outputs are at line level.

The VT-9M in many ways recreates the sound of the classic tube compressors of the 1960s, but using modern gain control circuitry. The audio path is entirely Class-A triode vacuum tubes, similar to classic designs but updated with improved modern passive components and computer-aided circuit optimization. Because of the unique qualities of vacuum tubes, the VT-9M has a clarity, transparency, and warmth that solid state compressors lack. Its modern design and construction allows the VT-9M to exceed the performance of vintage vacuum tube compressors.

It is designed for use in the professional recording environment. It accepts a low impedance (600 ohm nominal source impedance) balanced or unbalanced line level (nominal +4dBm) signal. There are controls for compression threshold, gain, attack and release times, and compression curve. Additional controls are used to insert a filter in the side chain and to switch the true VU meter between measuring gain reduction and output level. It is built to sound great for a long time, with top quality parts used throughout; the output transformers and many other components are custom-made for the VT-9M.