User's Manual

User’s Guide ADI-2 DAC v2.2 © RME

17.3 DSD Playback

While most DACs, even ones seen as 'Hi-End', leave the

user clueless during DSD operation, the ADI-2 DAC

continues to show level as well as spectral content. To be

able to show the analog I/Os audio signals on level meters

and Analyzer the DSP performs an additional DSD to PCM

conversion.

Analyzer and level meter show DSD signals in blue colour

for Green and Cyan, the current mode is therefore easy to

recognize (Amber gets a bit lighter).

During a DSD playback all DSP functions of all channels are temporarily disabled, even when

transmitting PCM. This is signalled in several menus by brackets around the (ON) and greyed-

out menu entries. An exception is the function Polarity, which stays available for one and both

channels.

Note

: The change between PCM and DSD causes a low volume click noise. For optimized

sound and fidelity, the ADI-2 DAC does not use any lossy analog volume control, hence can't

suppress the DAC's low level click noise.

You may notice clicks and cracks at the title change quite often with DSD, even when the next

title has the exact same sample rate. This is caused by the 1-bit format, which, unlike PCM,

requires absolute silence and DC freedom at the beginning and end of a title, so that the

transition as required by the 1-bit stream does not represent a random signal, which can sound

like a click or crack. Unfortunately, many freely available tracks are not 'clean' at the beginning

and the end. If these are played back one after the other by player software, the ADI-2 DAC's

level meters show that the noise to be heard does not originate from the ADI-2 DAC, but is

presented to the DAC as a signal to be played. The level meters are in the digital domain before

the DAC, so proof of a faulty input signal is easy.

17.4 DSD Record

Via USB the SPDIF inputs can record not only PCM but also DSD (DoP).

The source options and block diagram in chapter 31.16 are valid for DSD operation as well, with

both record and playback. The only difference: with DSD the circuit part DSP is bypassed (no

audio processing). In DSD mode all DSP functions are temporarily disabled. This is signalled in

several menus by brackets around the (ON).

Software to record DSD audio:

Name OS URL

VinylStudio Win/Mac www.alpinesoft.co.uk

Sound-It! Win/Mac http://www.ssw.co.jp

Pyramix Win www.merging.com

AudioGate4 Win/Mac www.korg.com