Audio Basis - articles about audio
DSD converter is software to convert Direct Stream Digital audio files to or from other formats. DSD sound files have extensions DSF, DFF, ISO (SACD ISO). PCM multi-bit formats (WAV, FLAC, AIFF, mp3, etc. files and CD-audio disks) can be used as source or target. Also, the such converter can resample DSD files. Read below how the converter works.
You can convert PCM to DSD audio files:
DVD-audio/video, Blu-Ray, DVD/BluRay/CD ISO are NOT supported.
For Modula-R version, SACD ISO, DSF, DFF are supported in proper configurations.
For ISO tracks, DSF, DFF longer than 3 minutes, FREE edition mutes 2-second silence in the output middle and has other restrictions
How to convert DSD to PCM audio files read here...
Format DSD is an implementation of 1-bit sigma-delta modulation. Range of sample rates that multiple 44100 Hz is used:
Bit depth is 1 bit.
Software DSD converter can contain inside:
1. PCM (multibit) modulator to delta-sigma modulation (1-bit), or
2. Sigma-delta demodulator (1-bit) to PCM (multibit), or
3. Both: modulator and demodulator.
4. Resampler and other processing.
DSD converter structure
DSD modulator provides a decreasing of bit number. It leads to increased noise level (quantization error).
The most useful part of an audio signal is located in the range 0 ... 20 kHz. The modulator "pushes" the noise energy to the range above 20 kHz. It's called "noise shaping".
Demodulator provides filtering of this noise. After the filtering, the most useful audio signal remains only. Practically, some artifacts remain in the demodulated signal.
A sigma-delta modulator (PCM to DSD) is sophisticated audio processing. It is a system with feedback. Hence it can lose stability. If the sigma-delta modulator (DSD modulator) loses stability, needs to restart it. As rule, it can't return to stable mode without external impact.
In general, design of sigma-delta modulator is a compromise between stability and noise level. More significant pushing of noise energy out of audible range may lead to stability loss. DSD modulator can lose stability due to overload.
For achieving a better signal/noise ratio inside audible range and keeping stability, the frequency band out of audible range must have a reserve by width. It may be achieved by increasing the sample rate.
Sample rate increasing is an easier way to have a wider band with lower noise.
Unfortunately, the author doesn't know exactly history of DSD creating. But, looks like, DSD64 sample rate was designed for transmitting 20 kHz band. As rule, a DSD demodulator design is easier, comparing a PCM one (read more). So replacement of 44 kHz/16 bit to DSD64 may give some technical advantages for implementation.
For transferring of 100 kHz-band signal with keeping or decreasing the noise floor, the easiest way is sample rate increasing.
Read more about sigma-delta modulator >
Sigma-delta demodulator (DSD to PCM) or DSD demodulator is a low-frequency filter, that removes modulation noise. The noise is located above the audible range.
This filter has 3 features:
A wider transient band allows decreased ringing audio, but pass more energy of noise of DSD modulator.
If expand passband, DSD's noise energy in the band is also increased. If the passband becomes narrower, ringing is increased.
So DSD demodulator is a balanced technical decision.
Read more about DSD decoder >
Before resampling a file, DSD is converted without losses to a multi-bit audio stream suitable for processing. After it, the stream is processed and converted back to DSD via modulator.
Resampling 1-bit audio cause little losses, comparable with losses for PCM resampling. There are losses defined by distortions of used implementation of processing.
However, the playback apparatus may have different distortion levels for various sample rates. Hence, resampling may give benefits, if DSD is converted to a sample rate that causes minimum distortions on a used DAC.
Resampling DSD audio file
for sample rate that causes minimum distortions on a used DAC
How to convert:
Read the guide on how to convert mp3 to DSD files...
Read manuals on how to convert:
Yes. Read how to convert PCM files to DSD format...
Read the article on how to convert FLAC to DSD files...
Read manual on how to convert DSD to FLAC files...
Read how you can convert DSF to FLAC...
You can convert FLAC to DSD, if it gives audible advantages of sound quality on your musical setup.
Digital conversion of DSD (2.8 MHz or more) to PCM (in instance, 24 bit / 96 kHz) is downsampling by nature.
Without filtering, downsampling causes spectrum folding distortions.
Thus, no way to convert DSD to PCM without filtering in the digital domain.
There is no mathematical difference between DSD and PCM for audio processing.
And, the author is not heard about 1-bit math.
Therefore, converting DSD to DSD is starting from transformation to multi-bit DSD (in instance, for AuI ConverteR 64-bit float / double precision) with the same frequency as the original Direct Stream Digital audio. Multibit DSD may be considered as PCM with a useful band of about 0 ... 30 kHz.
The converter software performs mathematical operations in 64-bit float / double precision.
Alternatively, these operations may be applied in other precision: 32-bit, 32-bit float or other.
After all operations, the multi-bit signal is re-modulated back into 1-bit DSD.
Before the re-modulation, the processed signal should be filtered to avoid overloading (clipping and broken stability) of the DSD modulator.
DSD files are audio files that contain audio in DSD format. Read more...
DSF file is a DSD audio file format. Read details...
DSD files contain high-resolution audio. Read more...
DSD is a sound format, that SACD contains.
Look at where you can download DSD music files:
Technically, FLAC is PCM format. And, actually, we compare PCM and DSD. Read more...
Both formats have advantages and disadvantages....
play DSD (.dsf, .dff) files with foobar2000...
DSD over PCM (DoP) is a way to transmit audio data via standard audio interface (USB). Read details...
DSD to FLAC conversion has some losses. However, proper conversion causes very small ones.
DSD converter software may contain:
Playback hardware may have different distortions for different modes (sample rate, bit depth, PCM/DSD).
Resampling DSD or conversion PCM to DSD and DSD to PCM may give benefits, if the target format is suitable for DAC mode, which causes minimum distortions.
January 8, 2023 updated | since April 6, 2017