User Guide Owner's manual

The following compression values are supported:
Compression Stereo Audio AC-3 Audio
no compression 24 bit native data (2975 kbps) 24 bit native data (2975 kbps)
pack 24 bits 24 bit data, full sample rate
(2250kbps)
16 bit data, zeros run length
encoded (430 kbps)
pack 20 bits 20 bit data, full sample rate
(1880kbps)
16 bit data, zeros run length
encoded (430 kbps)
pack 20 bits 20 bit data, full sample rate
(1880kbps)
16 bit data, zeros run length
encoded (430 kbps)
pack 16 bits 16 bit data, full sample rate
(1517kbps)
16 bit data, zeros run length
encoded (430 kbps)
decimate 2 16 bit data, 1/2 sample rate
(784kbps)
16 bit data, zeros run length
encoded (430 kbps)
decimate 4 16 bit data, 1/4 sample rate
(418kbps)
16 bit data, zeros run length
encoded (430 kbps)
The native uncompressed setting passes a full 24 bit payload plus 4 s/pdif control bits
updating on a continuous frame basis. Other modes only transmit the specified number of
bits and reduce the s/pdif control bits update rate to once per second.
Figure 38. Audio Adjustment Panel
Audio Input Selection
Audio input selection — only one audio source can be enabled at a time. Select either the
HDMI or Analog check box.
Analog input level (program audio) — the Analog input level is manually configured to
achieve an undistorted signal with the optimum signal to noise ratio.
Set the Analog Input Level setting to a value just larger than the maximum value (peak) that
will be input. The analog input measurement shows the current measured input level and
may be used as a reference to help determine the peak input level.
NOTE: This is a peak level adjustment that should be carried out when the input signal
is at a maximum level. The program audio stream should be connected to a suitable
decoder. If the audio is not being streamed, then the analog input measurement will
show disabled.
If the analog input measurement shows over‑range, the analog input level setting must be
increased until the over‑range condition clears. If the measurement is more than 2 dB below
the set input value, the input value should be reduced to be 1 dB greater.
NOTE: There is no input level control for digital audio. The output level may be adjusted
on the decoder.
VNM 250 • VNM 250 GUI Overview 54