TL Audio A4 - Manual (Page 11)

11
OPERATION.
Input Gain stage
The input gain is set to mirror the line level signal fed into the channel, upon input the
signal is a true representation of the input from your console or DAW.
Channel Pan Control
A pan control is present for each input channel to control the stereo position of the
signal fed into it, this is ideal for combining stereo and mono feeds on different
channels.
Input switching
Input switches are located on the left hand side of the front panel. Input channels 1-8
and 9-16 can be independently switched between +4 and -10dB input levels to cater
for balanced and unbalanced situations. There is also the facility to independently
switch the insert points and the master output level between +4 and -10dB.
Tube Stage Drive and Peak LEDs.
These LEDs indicate the drive level to the tube, or valve, stage. The Drive LED is a
variable intensity indicator, starting to glow when the tube harmonic distortion is
around 1%, and being fully illuminated at approximately 5% harmonic distortion. The
distortion is predominatelly second harmonic, unless very high drive levels are used,
in which case the tube is eventually pushed into harsher saturation, indicated by the
tube Peak LED.
Tube Drive Control
The tube stage is only active in the circuit of the A4 when switched ‘on’. Once
activated into being part of the circuit, the amount of ‘tube sound’ or even harmonic
distortion introduced, is then controlled on the A4 via the rotary knob control ‘tube
warmth’. This makes it very easy to control how much colour you would like to
introduce to your summed signal and gives you the choice to stay neutral too.