TL Audio M4 - Manual (Page 13)

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2-Track Return
When recording the stereo mix output onto DAT or CD-R, for example, it is
sometimes useful to be able to monitor the output from the mastering machine, in
place of the mixer stereo output, as confirmation that the signal is actually being
recorded (this is particularly useful when using a four headed DAT machine or a
three -headed analogue 2T machine, since the off-tape signal can be monitored).
This is achieved by selecting the 2T Return switch near the monitor level control.
This facility may also be used for playback after recording.
Loudspeaker Mute
This switch mutes the rear panel monitor output. This is particularly useful when
using headphones, enabling the main monitors to be muted without needing to
turn off their amplifiers. This is also useful for temporarily muting the monitors
without needing to alter any fader levels, for instance during a telephone call.
Metering
Two illuminated VU meters on the M4 will normally monitor the main stereo
output, but automatically switch to monitor the PFL buss when any PFL switch is
engaged. Similarly, when the 2T return is selected as the monitor source (via the
relevant select switch - see section 4.22) the meters will automatically switch to
monitor the 2T return. The meters are calibrated to indicate 0VU when a signal
level of +4dBu is generated at the main outputs. A pair of red Peak LEDs operate
on the stereo buss as a conventional warning that clipping is about to occur. The
LEDs illuminate at a threshold of +21dBu, when there is less than 5dB of
headroom remaining on the main outputs. Normal operation would be to set the
stereo buss fader levels so that occasional illumination of the Peak LEDs occurs on
loud transients.
Digital Output Option
The optional DO8 card can be fitted to the back of the M4 and each card provides
8 channels over ADAT lightpipe. This professional protocol makes for easy
connection when conducting computer based recording, and makes the M4 the
perfect front-end solution for digital recording set ups.
There is also the optional DO2 card that fits into the back of the master section of
the M4 and provides stereo digital output in SPDIF format (RCA Phono
connectors). The DO2 is has a fixed 24 bit word length, but the sample rate is
switchable between 44.1, 48, 88.2 and 96 kHz. These are selectable from the back
of the digital card.