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MY
DAI
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Isolated
Data Acquisition Front End for High SNR Recording
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General
Description ... ... |
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It's
interesting to record the sound of nature, like singing of bird, rain dropping,
and thunder. On hearing these sound, our soul feels released, especially
for people who lives in big city. |
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We always use portable
MD as recorder. But the internal ADC for a normal MD is not good enough.
Its SNR should be in the range of 80 to 85 dB. That's not so quiet when
recording at night in the forest.
So it's necessary
to use an individual data converter with higher SNR as front end and connect
to the MD using optical cable. Most MD recorder has a optical line in
port.
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Or, alternatively,
use a USB to optical converter ... ...
The heart of the converter
board is a Crystal CS5331 18bit stereo ADC chip. The companion chips are
the preamplifier, SPDIF transceiver and some glue logic.
The PCB should be carefully routed for superb
SNR performance. Special care should be taken for the ground traces.
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Here
are some brief measurement charts of the performance ... ... |
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