TL Audio 5051 - Manual (Page 12)

is turned down. Failure to do so may result in a thump in your
monitor loudspeakers or PA system.
4.3 Line
Input.
A line level signal should already be at about the correct operating level, but
this may be checked by monitoring the level on the output meter, with the
compressor bypassed and the output gain at 0dB. The input gain should be
adjusted until the meter reads about 0VU at normal audio level, when set to
read ‘I/P’.
4.18 Instrument
Input.
The front panel instrument input socket is suitable for low level sources such
as hi impedance microphones, pick ups or passive guitars, and higher level
sources such as active guitars and keyboards. To cater for this wide variety of
sources, the 5051 has a large amount of gain available, and care should be
taken to avoid applying excessive input gain with a high level source.
4.19 30dB
Pad.
Occasionally – when using sensitive condenser microphones – the source
signal may be too loud for the input preamp. In this situation, to avoid any
overloading or distortion of the mic preamp stage, the 30dB pad can be used
to reduce the input gain to a more manageable level. The 30dB pad only
applies to the microphone input.
4.20 90Hz
Filter.
The high pass filter switch restricts the low frequency response of the preamp,
to effectively remove rumble of 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
the mic, line and instrument inputs.
4.21 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 0dB to +12dB.