TL Audio 5060 - Manual (Page 11)

8
4.5
Mic Gain.
The Mic Gain control sets the level of the microphone input signal prior to the Input Gain control. There are 4-switched level
positions: -20, 0, +20 and +40dB, with a further +/- 20dB available on the Input Gain control. For normal operation it is
recommended to keep the Mic Gain setting at the +40dB position, with any fine adjustments to the input signal level made
by either boosting or reducing the Input Gain control. Keeping the Mic Gain at its maximum setting (+40dB) helps to keep
the noise figures as low as possible. For extremely high-level signal sources - such as close-mic’d drums - it may be necessary
to reduce the Mic Gain position to prevent input overload.
4.6 Input
Gain.
The Input Gain control sets the level of the signal fed to the input stage of the compressor, and is variable between -20dB
and +20dB. This allows a wide range of signals to be fed into the 5060, and also allows the valve stages to be driven to a
variable degree. Each channel of the 5060 has 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”. At the same time the output level can be turned down to preserve the same level at the
outputs, 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 5060 hard!
As well as driving the valves harder, increasing the Input Gain control setting will also tend to push the signal towards and
possibly over the compression threshold setting, so this control will have a pronounced effect on the amount of compression
taking place, even in the Preset modes.
The Input Gain control is active at all times, whether the Program control is set to Manual or Preset modes.
4.7
90 Hz Low Cut Filter.
The low cut (high pass) filter switch restricts the low frequency response of the preamp, to effectively remove rumble or LF
noise from the signal. The filter can be useful in restricting “popping” on vocals or even low frequencies caused by contact
with microphone stands or microphone cables. Popping is an undesirable thump that is caused by close-miking certain spoken
or sung letters, namely “P” or “B”. These particular letters cause a sudden expulsion of air that can result in an audible
thump. As this thump has a lot of low frequency content the high pass filter can help to reduce the problem, as can using a
pop filter (a device usually made out of nylon material similar to stockings) suspended in front of the microphone. The 90Hz
filter is active on mic, line and instrument inputs.
4.8
Drive and Peak LEDs.
The yellow Drive LED provides a visual indication of the signal level through the valve stages, and therefore the extent of
“warming” or valve character being introduced. The Drive LED will gradually illuminate as the input level or gain is increased,
over the range 8dB to +18dB.
The red Peak LED operates as a conventional warning that clipping is about to occur. The operating level of the entire signal
chain is monitored, and the LED illuminates when there is less than 6dB of headroom remaining. Normal operation would be
to set the input gain so that the Drive LED is regularly illuminating, with occasional lighting of the Peak LED on transients.
However, it is possible to add gain further down the 5060 signal path which will cause the Peak LED to illuminate at a lower
level of Drive. This situation implies that a high level of “clean” signal is present, without driving the valves hard.