HD621 HDMI Audio Processor
User Guide
Overview
HD621 product highlights
SmartLink output
MMHR output
Up/downsampling of digital audio
FIFO buffering
Lip-sync delay
Front panel
The front panel provides a standby indicator, which is off when
the unit is active, and six indicators indicating which HDMI input
is selected. The
Manual
button allows you to step through the
inputs.
SmartLink output
These four phono sockets each carry a pair of digital audio
channel signals at up to 96kHz sample rate: 1/2, 3/4, 5/6 and
7/8. These are encrypted to Meridian High Resolution (MHR)
specifications when carrying high resolution data.
Up/downsampling of digital audio
The MMHR and SmartLink outputs can be set to deliver either
standard (44.1/48kHz) or high resolution (88.2/96kHz) sample
rate digital audio, with resolution enhancement of up to 24-bit.
When set to standard rates, the output is either 44.1kHz
or 48kHz irrespective of the input rate, high sample rates
being downsampled by a factor of two or four as appropriate.
44.1kHz and 48 kHz rates are unchanged.
When set to high rates, the output is always either 88.2kHz or
96kHz, irrespective of the input rate. Standard sample rates are
upsampled by a factor of two using Meridian’s powerful DSP
technology, so that input signals of 44.1kHz and 48kHz are
output at 88.2kHz and 96kHz respectively.
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FIFO buffering
In addition to the features noted above, the HDMI audio
processor de-jitters digital audio received via HDMI using two
FIFO (First In, First Out) buffer systems. This ensures that the
audio extracted from the HDMI stream is of the highest quality.
Lip-sync delay
The HD621 also includes a configurable audio delay of up
to 85ms to allow lip-syncing in the event that the display
introduces an appreciable delay in the video presentation.
