Tube-Tech LCA 2B Stereo Tube Compressor/Limiter

The Tube-Tech LCA 2B is a two-channel unit with an independent compressor and limiter per channel. The unit is all tube based (except for the power supply and side chain circuit). The VCA (1 dual triode) is placed between the input transformer and the output stage (2 dual triodes). The audio signal is picked up after the VCA and fed to the side chain circuit. The control signal from the compressor and from the limiter is combined and sent to the link switch and to the control amp, which feeds the VCA. The two bi-directional link busses are accessible at two 1/4" stereo jack sockets on the rear panel. The channels can be linked together for stereo applications and also linked to other LCA 2B's via the two link busses and a standard stereo jack/jack cord.

The compressor has six att/rel presets as well as manual control. The limiter att/rel is fixed. The LED display is fed from the con-trol amp. The limiter LED is fed from the limiter buffer.The audio path is fully symmetrical from input to output. Input and output have fully floating transformers. All DC voltages are stabilized, ex-cept the anode voltage for the output stage.

Separate compressor and limiter:

Compressor

• Variable ratio from 1,6:1 to 20:1
• Variable threshold: off to 10 dB
• Selection between six presets and manual controlled att/rel

Limiter

• Variable threshold: off to 0 dBu
• On/off switch
• LED indication

General

• Frequency response @ -3 dB: 5 Hz to 50 Khz
• Low noise: < -85 dBU @ 10 dB gain
• Output gain control