Tube Tech LCA 2A Stereo Compressor - Manual

TUBE-TECH LCA 2A
compressor and limiter
DESCRIPTION:
The TUBE-TECH LCA 2A is a two channel unit with an independent com-
pressor and limiter per channel. The unit is all tubebased (except for
the power supply and sidechain circuit). Input gaincontrol is placed
before the input transformer. The VCA (1 dual triode) is placed between
the input transformer and the outputstage (2 dual triodes). The audio
signal is picked up after the VCA and fed to the sidechain 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
bidirectional link busses are accessible at two 1/4" stereo jack sockets
on the rear panel. The channels can be linked together for stereo appli-
cations and also linked to other LCA 2A's via the two link busses and a
standard stereo jack/jack cord.
The compressor has six attack/release presets as well as manual control.
The limiter attack/release is fixed.
The LED display is fed from the control 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, except the anode voltage for the out-
putstage.
COMPRESSOR INTERCONNECTION:
The sidechain sockets for interconnection of several compressors is
located on the rear panel.
A switch (LINK 1, LINK 2) on the front selects which compressors are
interconnected, and on which bus they are connected. If you select LINK
1 on both channels, they will perform exact the same gainreduction.
Having several connected compressors in a rack, you can select which
compressors you will have working together.
By selecting e.g. compressor 1 ch. 1 on link 1, compressor 2 channel 2
on link 1 and compressor 3 ch 1 on link 1, they are now interconnected
and all three will perform the exact same compression.
The interconnection implies, that the unit which performs the most
compression is controlling the others.
To choose which one you want to control, select the attack/release time,
the threshold and the ratio on that unit, and turn the threshold fully
counterclockwise on the reminding compressors.
It is of course possible to have all the interconnected compressors
control each other simultaneously.