miniDSP Ltd, Hong Kong /
/ Features and specifications subject to change without prior notice
18
5.4
DSD
PLAYBACK MODE
The HA-DSP detects DSD (Direct Stream Digital) audio sent to it over the USB connection and switches to play it
automatically. The data must be sent in DSD-over-PCM format (DoP). When in DSD playback mode,
all audio
processing except for input selection and final stage volume is disabled
.
When the HA-DSP is in DSD mode, LEDs 2 and 3 are on.
What is DSD?
DSD is a relatively recent audio format. It is the form in which data is stored in SACDs. Regular CDs, in contrast,
store data in PCM (pulse code modulation) format.
DSD audio will be contained in files ending in the
“.dsf” or “.dff”. You will be playing DSD only if you have
purposely downloaded DSD files and use a DSD-capable audio player to play them. Regular audio from your
computer will always be in PCM format. Common file formats such as FLAC, WAV, AIFF, and MP3 are all PCM.
How do I play DSD?
By using a DSD-capable audio player app on your computer, phone or tablet. These days, most audiophile-level
music players are DSD-aware. Typically, you will need to tell the player app (e.g. in its Preferences settings) that
the HA-DSP can play DSD using DSD-over-PCM (DoP).
What DSD formats are supported?
The HA-DSP supports single-rate DSD (aka DSD64) and double-rate DSD (aka DSD128). A DSD-capable audio
player will detect the sample rate from the DSD file and send the correct signal over USB to the HA-DSP.
Why is audio processing disabled in DSD playback mode?
The DSD format is not conducive to audio processing. When the HA-DSP detects DSD audio, it simply bypasses
the digital signal processing (DSP) chip and sends the DSD data directly to the DAC chip.
What if I want to keep the processing while playing DSD files?
You will need to tell the player to convert the DSD to PCM before sending it to the HA-DSP. Some players will do
this automatically, while others may need a specific setting to convert to PCM.
Why is it important that I know that processing is disabled in DSD mode?
Any EQ or cross-feed that you have set up in the HA-DSP will not function when playing a DSD file. In addition,
the gain settings in the input section will (in effect) be set to 0 dB. If you have applied a lot of attenuation here,
you will get a jump in volume when you switch from playing a PCM file to playing a DSD file. Usually, this is not a
problem as the input attenuators are not usually set very far below zero. You just need to be aware that the
volume
could
change.
In DSD playback mode, all audio processing including metering in the plugin is disabled. This may
result in a sudden change in volume.
