Dsd Playback; Dsd Record; Beyond - RME Audio ADI-2 Pro User Manual

19.3 DSD Playback

During a DSD playback all DSP functions of the respective
stereo channels are temporarily disabled. This is signalled in
several menues by brackets around the (ON). Analyzer and
level meter show DSD signals in blue color, the current mode
is therefore easy to recognize.
The change between PCM and DSD causes a low volume
click noise. For optimized sound and fidelity, the ADI-2 Pro
does not use any lossy analog volume control, hence can't
suppress the DAC's click noise.

19.4 DSD Record

The ADI-2 Pro converts the analog input data not only to PCM, but optionally also to DSD. Via
I/O - Analog Input - AD Conversion the AD-converter can be switched from PCM (Default) to
DSD. Based on the current mode the DSD data are then sent to the outputs AES and SPDIF
(DoP), USB (DoP via ASIO), and the analog outputs 1/2 and 3/4 (re-converted by the DAC).
The option DSD is not available in CC mode Multi-channel. The unit has to be configured to
stereo mode to change from PCM to DSD AD-conversion.
All modes, routings, source options and block diagrams of chapter 17 are valid for the DSD
operation as well, with both record and playback. The only difference: with DSD the circuit part
DSP is bypassed (no audio processing).
A mixed operation is possible. During a DSD recording, also AD conversion, a PCM file can be
played back and monitored via DA. Even a playback of DSD via channels 1/2 and simultaneous
monitoring of AES or Analog In via output 3/4 is possible, no matter whether the sources are
PCM or DSD.
Limitations exist, but they are identical with PCM and DSD. For example the limit of 192 kHz on
the digital I/Os AES and SPDIF means that in mode AD/DA only DSD64 can be used, not
DSD128 and DSD256. That's not different to PCM, where the higher sample rates 384 and 768
kHz can't be used. And the common clock does not allow any combination of modes. For ex-
ample a recording done at DSD64 (176.4 kHz) does not allow a simultaneous playback of 192
kHz; again the same limitation applies in PCM mode.

19.5 Beyond...

For the first time the ADI-2 Pro enables configurations, settings and applications that might gi-
ves answers to a lot of questions. Is there really a sonic difference between different DA-filters
with different impulse response properties? Just try it! Is there really a difference in sound be-
tween DSD to PCM and DSD Direct? Just try it! Does an AD/DA converter chain sound different
with different sample rates? Just try it! Does the same converter chain sound different - and
how does it sound at all - if one uses DSD? Just try it!
User's Guide ADI-2 Pro © RME
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