TL Audio 5052 - Manual (Page 12)

4. OPERATION
4.1 Input Stage.
The Input Gain control sets the level of the mic, line or instrument input into the 5052
preamp stage. The signal source is selected by the 4-position switch adjacent to the
Input Gain control. Input choices are Mic 48V (for condenser microphones that
require phantom power), Mic (for dynamic or most ribbon microphones), Line and
Instrument. The Instrument input allows high impedance instruments such as guitars
or a bass etc to connect directly into the 5052 and eliminates the need for a Direct
Injection Box. A wide range of signals can be fed into the 5052, and the Input Gain
control also allows the valve stages to be driven to a variable degree. After the
preamp stage the signal passes through a triode valve stage positioned between the
input circuit and the compression stage. Increasing the input gain pushes more signal
level into the valve, thus generating more harmonic distortion and creating that
special “valve sound”. This is indicated by the yellow ‘Drive’ LED which will glow more
intensely as the level increases. At the same time the output level can be turned
down to preserve the same level at the output, so a choice of sounds is available.
For a more pronounced valve sound, turn up the input gain and reduce the output
gain, and vice versa for a cleaner sound. Don’t be afraid to push the 5052 hard!
As well as driving the valves harder, increasing the Input Gain control setting will also
have a pronounced effect on the amount of compression as the threshold will remain
constant as the input level increases. If the input gain is adjusted, the threshold can
be adjusted accordingly to maintain a similar amount of compression.
4.2 Microphone Input.
When using the 5052 with a microphone source, care should be taken not to apply
too much gain at the input. Start with the input gain control set to minimum, and the
output master at the mid-point (12 o’clock position). The input gain can then be
gradually increased until the VU meter registers about 0VU on normal signal level,
when set to read ‘I/P’. The master output level should then be adjusted to produce
the required output.
CAUTION: Never switch phantom power on or off, or plug / unplug a
microphone with phantom power applied unless the output level control is turned
down. Failure to do so may result in a thump in your monitor loudspeakers or PA
system.