TL Audio A3 - Manual (Page 12)

11
OPERATION
Input Stage.
The input gain control sets the level of the mic, line and instrument signals into the
Ebony A3. The 2-position button above the input gain and ‘Tube Warmth’ knob
selects the signal source. Input choices are ‘Mic’ (for dynamic or most ribbon
microphones and condenser microphones that require phantom power), ‘Line’ and
‘Instrument’. For condenser microphones, you should also press the 48V button to
activate phantom power. The Instrument input allows high impedance instruments
such as guitars or a bass etc to connect directly into the Ebony A3 and eliminates the
need for a DI (Direct Injection) Box. For even better performance you also have a
button at the input stage to enable you to switch between high and low impedance
instrument inputs. 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 re-
adjusted accordingly to maintain a similar amount of compression.
Microphone Input.
When using the Ebony A3 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 ‘IN’. 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 controls turned down. Failure to do so
may result in a thump in your monitor loudspeakers or PA system.
Line Input.
A line level signal should already be at about the correct operating level, but
monitoring the level on the output meter, with the compressor bypassed and the output
gain at 0dB, could check this. The input gain should be adjusted until the meter reads
about 0VU at normal audio level, when set to read ‘IN’.
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, as it is switchable to high or low sensitivity.