M-AUDIO SAM - Manual (Page 12)

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input signal present the mode LED will flicker very rapidly. It will
stop flickering and remain lit if a valid signal is present.
Note: The ADAT In and ADAT Out jacks expect ADAT-compatible
multi-channel signals (ADAT Optical Data Interface format), as
opposed to optical S/PDIF standard. SAM does not support con-
version to and from optical S/PDIF formats, although there are other
products on the market that will convert between optical (Toslink)
and coax S/PDIF formats (the Midiman Co2 product for example).
Note: For best results, use a good-quality S/PDIF cable. The cable
should be coaxial with 75-ohm impedance. A good quality video
dubbing cable (for example) has these characteristics, as do more
expensive professional-quality S/PDIF cables.
In any of the modes, the output sample rate will always be synchro-
nized with the input sample rate. In other words, when using ADAT-
to-S/PDIF modes, the sample rate will be determined by the ADAT
optical stream; when using S/PDIF-to-ADAT mode, the sample rate
will be determined by the S/PDIF optical stream.
The LED output level displays are peak meters that show real-time
output signal levels in all modes. Output level in all direct modes
will precisely match that of the source level. Output level in mix
mode is controlled by the sum of the individual rotary Gain controls.
Digital clipping is occuring when the red “-1/Clip” LED is lit.
Note: Excessive clipping (causing the red “-1/Clip” LED to light
often or to stay lit) may cause extreme distortion and should be
avoided. An occasional CLIP reading is sometimes OK -- it's best
to let your ears be the judge! Generally speaking, the maximum
level before clipping (the yellow “-3” LED lighting occasionally or fre-
quently) is the best level to maintain.
The Mix mode is a special mode in which the SAM gain and pan
pots are active. Each incoming ADAT channel may be independent-
ly attenuated and panned within a stereo output signal. Each Gain
control may be set anywhere from infinite attentuation (turned all the
way counter-clockwise) to 0 dB or “unity gain” (turned all the way
clockwise). This level is also influenced by the position of the Pan
control. In the center detent position, a Pan control attenuates the
signal by 3dB. This practice of slight attenuation in the center posi-