LIVERPOOL Tube Compressor
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TECHNICAL NOTES
SWITCHING ON
The power switch is located on the right side of the front panel. Flip the
switch up to turn on the LIVERPOOL compressor and down to turn it off.
Do not operate this switch up and down rapidly, as it may cause damage.
TUBE LIFE
As with all tubes, their quality degrades with age. This is due to cathode
emission, a natural process found in all tubes. We recommend that you
have your unit checked every 4-5 years, depending on usage. One
symptom of failing tubes is increased noise floor and performance
changes.
NOTE
Allow the LIVERPOOL to warm up before operating. This unit employs
high voltage tubes and reaches optimum operation within approximately
twenty minutes. Any adjustments such as meter calibration should be
performed when the unit had time to warm up to operating temperature.
OPERATION
The principle of operation of this unit is based around a Mu tube, an all
glass miniature VHF dual triode, remote cut-off tube.
This is the gain
reduction tube. This tube is re-biased by the 6AL5 vacuum tube rectified
side-chain control voltage which causes the Mu tube to smoothly change
its mutual conductance.
The benefits of utilizing a variable mutual
conductance vacuum tube as the 'heart' of the compression function is
that a widely varying range of input signals can be handled quickly
without introducing harmonic distortion.
As with all compressors there will be little change of gain reduction with
various settings of ATTACK and RECOVERY controls using a sine wave
source. With music there will be changes in the amount of gain reduction
with changes of these controls.