15
7
POLARITY INVERT
Pressing this button inverts the polarity of the digital signal, to compensate
for polarity differences during the recording process. Some recordings may
simply “sound better” when this function is active.
While
polarity invert
is selected, the LED above the button will light.
Note
:
polarity invert
doesn’t affect the digital outputs, and isn’t available
for inverting the polarity of digital signals to be recorded.
Note
:
polarity invert
may be operated by infrared remote control, but
only when the Nº30.5 is connected to compatible Mark
Levinson components such as the Nº31 Reference CD Transport.
Complete instructions are included in those components’ oper-
ating manuals
.
8
COPY PROTECT LED
This LED lights when the Nº30.5 detects encoded copy protection in the
digital program being processed.
9
AES/EBU LED
The
aes/ebu LED
lights when the Nº30.5 detects that the digital program
being processed conforms to the AES/EBU (
Audio Engineering Society/Eu-
ropean Broadcast Union
) professional standard. This LED indicates the
presence or absence of certain encoded information in the digital signal. It
does
not
indicate that the AES/EBU connections (a connection standard
written by the same group) are being used. Playback of non-AES/EBU CDs
or DATs won’t activate the
aes/ebu LED
, even if the associated transport is
connected according to the AES/EBU standard
10
EMPHASIS LED
The compact disc standard, as created by Sony and Philips, allows a high-
frequency boost to be employed during recording. This boost, called re-
cording pre-emphasis, increases the signal-to-noise ratio at high frequencies,
but must be countered by a high-frequency cut before playback to restore a
recording’s normal frequency response. De-emphasis may be done as the
recording is being mastered, or the compact disc (or digital audio tape)
may be made with the pre-emphasis still on, and the de-emphasis per-
formed in the playback unit.
In the Nº30.5, the de-emphasis filtering is done in the digital domain.
The
emphasis LED
lights when the Nº30.5 detects recording pre-emphasis
in the digital program being processed, and subsequently employs its de-
emphasis circuitry (see “Specifications”).
Note:
The de-emphasis circuitry of the Nº30.5 is designed to be
compatible with all known digital standards. However, it is
possible for the emphasis LED to light in error when there is
no disc being played. This is not a malfunction of the Nº30.5.
Rather, it is the result of the transport generating ambiguous
signals in the absence of a spinning disc to read. You may
never see this condition. Even when the condition exists, it
has no effect on sonic quality, as it can only occur when
there is no disc playing.
