# DSD For Dummies
**URL:** https://forum.psaudio.com/t/dsd-for-dummies/37154
**Category:** Network Audio
**Created:** [April 5, 2024, 3:37pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154 "2024-04-05T15:37:05Z")
**Posts on this page:** 15
**Page:** 1
### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 5, 2024, 3:37pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/1 "2024-04-05T15:37:05Z")
**What Makes DSD Audio (Potentially) Unique. A DSD Primer. Or DSD For Dummies.**
- Super(?) High Sample Rate.
- Delta Sigma Modulation.
- 1-Bit Samples.
- Noise Shaping.
- Low Quantization Noise.
- Low Distortion.
**DSD, Direct Stream Digital** is a file format trademarked by Sony and Philips. The format was initially created for archiving audio signals and then commercially used for SACDs. At the time of this writing, DSD audio files are available as media downloads without needing to use the physical media.
**Super High Sample Rates.**
DSD 64 is called so because the sample rate or sample frequency is 64 times higher than the CD sample rate of 44.1KHz (44,100) samples per second.
64 x 44,100 = 2,822,400. Again, samples per second.
DSD 128
128 x 44,100 = 5,644,800 samples per second.
And so on.
**Delta Sigma Modulation (Sigma Delta Modulation. Same. Same. Mostly).**
Delta-sigma modulation, simply put, is a method for encoding signals into digital signals. It is just a different method of encoding than PCM (Pulse Code Modulation) is.
What delta-sigma modulation does differently is that it does so at a higher sample rate than PCM does, but with the higher sample rates, it only needs 1-Bit samples.
The delta-sigma modulation process uses a negative feedback loop to correct for the quantization errors that are inherent in converting an analog signal to a digital signal.
About the “errors”: Think pushing a wheelbarrow up or down a flight of stairs instead of up or down a ramp. The vertical distance between the steps (digital signal) is missing the slope (analog signal). No matter how low of a height difference there is between the steps, there will always be a ‘bump’. Bumps lead to errors which lead to noise. There is a mathematical remainder (error, noise) between the digital steps that the analog slope provided before the A to D conversion.
Delta means difference. Sigma means Sum.
**1-Bit Samples.**
Due to the high frequency sampling and the DSM process of quantization, with the negative feedback loop, only 1 (ish) bit is needed. Basically, the single bit indicates if the current sample voltage is higher or lower than the sample taken before it. When the bits indicating up or down are mapped out, a wave, like an analog wave, is the result. Hence the need for only 1 (ish) bit.
**Noise Shaping.**
The errors that are there from the conversion of an analog to a digital signal are moved up and out of the way. The noise that is the result of the errors created by quantization is still there but noise shaping places the noise in bandwidths outside of the desired frequency range, the frequency range of the original signal. When the file is accessed, a filter blocks out the noise that now resides in the higher bandwidths. The result is a higher Signal-to-noise ratio.
Essentially, Noise Shaping, sweeps the noise that comes from the quantization errors under the rug so that we do not see them. Or, as with audio files, we do not hear them.
**Low Quantization Noise.**
Noise Shaping provides this. Again, the noise is still there, it is just in places that are more out of the perceivable way. So it sounds like less noise is in the playback of the file.
**Low Distortion.**
For audio files (and audiophiles) distortion of an audio signal is usually very unwanted. Distortion occurs when the wave of an output file does not lined up like it is directly on top of the source file. When analog signals are converted to digital signals, there will be distortion – steps vs slope.
And again, Noise Shaping and, perhaps, more so, the high sample rate are our audiophile friends so that a file can be played back with low distortion.
**Putting It All Together.**
All the above make for a clean natural sounding audio file. If the original analog source file is good, the converted DSD file should also be good.
Yes, as in most things, if garbage in, then garbage out. So, DSD is not a magic bullet solution for all genres of music or for specific recordings.
So, What Makes DSD Audio Files Special?
**In a nutshell:**
The High Sample Rates.
Delta Sigma Modulation
Noise Shaping.
Without these you cannot achieve the resulting:
- Low Quantization Noise.
- Low Distortion.
**Adding What @dvorak So Eloquently Wrote To Sum It Up (To Have It All In One Place):**
> [@dvorak](#):
>
> Let me highlight that the specific magic of DSD is its 1-bit-ness, and the way that helps is that it makes it much easier to implement a DAC circuit with extremely high linearity (which means low noise and distortion).
>
> It’s also the case that to make 1-bit-ness deliver useful signal-to-noise ratios in the audible frequencies, it is _necessary_ to sample at extremely high rates and use sigma-delta modulation to shift the quantisation noise way up into the ultrasonic region.
>
> And as a consequence of the high sampling rate and noise shaping, we can avoid the CD-era mistake of using “brick wall” low pass filters which contribute greatly to what people have come to think of as the “sound of digital”.
>
> So with high linearity, low noise, low distortion and the lack of “digital-sounding” filters, DSD raises the bar on how good digital audio can be.
**Further Information.**
As this is not all encompassing, here are some links to further information:
A Deeper Dive (Thanks to @tedsmith and Richard Murison)
> **[DSD – Is It PCM, Or Isn’t It?](https://www.psaudio.com/blogs/copper/dsd-is-it-pcm-or-isn-t-it)**
>
> A few weeks back, a prominent person in the audio community shared with me their opinion that DSD is a different thing entirely from PCM, and was surprised to hear me insist otherwise. On the face of it, of course, they are indeed very different...
> **[Direct Stream Digital](https://en.wikipedia.org/wiki/Direct_Stream_Digital)**
>
> Direct Stream Digital (DSD) is a trademark used by Sony and Philips for their system for digitally encoding audio signals for the Super Audio CD (SACD).
> DSD uses delta-sigma modulation, a form of pulse-density modulation encoding, a technique to represent audio signals in digital format, a sequence of single-bit values at a sampling rate of 2.8224 MHz. This is 64 times the CD audio sampling rate of 44.1 kHz, but with 1-bit samples instead of 16-bit samples. Noise shaping of the 64-times oversa...
> **[Delta-sigma modulation](https://en.wikipedia.org/wiki/Delta-sigma_modulation)**
>
> Delta-sigma (ΔΣ; or sigma-delta, ΣΔ) modulation is an oversampling method for encoding signals into low bit depth digital signals at a very high sample-frequency as part of the process of delta-sigma analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). Delta-sigma modulation achieves high quality by utilizing a negative feedback loop during quantization to the lower bit depth that continuously corrects quantization errors and moves quantization noise to higher frequencie...
> **[Pulse-density modulation](https://en.wikipedia.org/wiki/Pulse-density_modulation)**
>
> Pulse-density modulation, or PDM, is a form of modulation used to represent an analog signal with a binary signal. In a PDM signal, specific amplitude values are not encoded into codewords of pulses of different weight as they would be in pulse-code modulation (PCM); rather, the relative density of the pulses corresponds to the analog signal's amplitude. The output of a 1-bit DAC is the same as the PDM encoding of the signal.
> In a pulse-density modulation bitstream, a 1 corresponds to a pulse o...
> **[Pulse-code modulation](https://en.wikipedia.org/wiki/Pulse-code_modulation)**
>
> Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps.
> Linear pulse-code modulation (LPCM) is a specific type of PCM in which the quantization levels are linearly unif...
> **[Quantization (signal processing)](https://en.wikipedia.org/wiki/Quantization_(signal_processing)#)**
>
> Quantization, in mathematics and digital signal processing, is the process of mapping input values from a large set (often a continuous set) to output values in a (countable) smaller set, often with a finite number of elements. Rounding and truncation are typical examples of quantization processes. Quantization is involved to some degree in nearly all digital signal processing, as the process of representing a signal in digital form ordinarily involves rounding. Quantization also forms the c...
**A Few Videos:**
Ted explains DSD - Paul McGowan, PS Audio
[ ](https://www.youtube.com/watch?v=xafLYw6EuZ4)
PCM vs DSD - Paul McGowan, PS Audio
[ ](https://www.youtube.com/watch?v=BIvBo4oLh3s)
DSD Explained part 1 - The Hans Beekhuyzen Channel
[ ](https://www.youtube.com/watch?v=hXFIq11JAas)
**And For Advising Or Joining In The Conversation That Started It All:**
> [@WAV to FLAC File Conversion](https://forum.psaudio.com/t/wav-to-flac-file-conversion/36760):
>
> Howdy all, Checking google and finding it confusing. I have many uncompressed WAV files (1141 kbps) and I would like to convert them to FLAC (192 kbps). Anyone have experience with a good converter? I am on a Windows 10 machine and I created these files recording some old cassette tapes (totally out of print and not on any streaming services) using an old program called CoolEdit 2000. I just want to ensure getting 192kbps flac files from the uncompressed wav files. Thanks! -Gil
**With Thanks To:**
@gfuhrer
@Baldy
@terzinator
@tedsmith
@scotte1
@dvorak
@MikeK
@waymanchen11
@aangen
---
### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 5, 2024, 3:38pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/2 "2024-04-05T15:38:29Z")
If any corrections or ideas need to be changed or edited, please reply and I will be happy to review them.
Thanks!
mrcandude 🕶
---
### Author:  [@gfuhrer](https://forum.psaudio.com/u/gfuhrer)
#### Post date: [April 5, 2024, 7:36pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/3 "2024-04-05T19:36:41Z")
This is awesome @mrcandude!! Thanks!!!
---
### Author:  [@dvorak](https://forum.psaudio.com/u/dvorak)
#### Post date: [April 5, 2024, 11:40pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/4 "2024-04-05T23:40:18Z")
A very solid effort, and I love the spirit of sharing 👍
Let me highlight that the specific magic of DSD is its 1-bit-ness, and the way that helps is that it makes it much easier to implement a DAC circuit with extremely high linearity (which means low noise and distortion).
It’s also the case that to make 1-bit-ness deliver useful signal-to-noise ratios in the audible frequencies, it is _necessary_ to sample at extremely high rates and use sigma-delta modulation to shift the quantisation noise way up into the ultrasonic region.
And as a consequence of the high sampling rate and noise shaping, we can avoid the CD-era mistake of using “brick wall” low pass filters which contribute greatly to what people have come to think of as the “sound of digital”.
So with high linearity, low noise, low distortion and the lack of “digital-sounding” filters, DSD raises the bar on how good digital audio can be.
---
### Author:  [@tedsmith](https://forum.psaudio.com/u/tedsmith)
#### Post date: [April 6, 2024, 3:44am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/5 "2024-04-06T03:44:43Z")
Another data point: Richard Murison wrote this for Copper a while back. He took flak from all quarters for it, but it is correct:
[DSD – Is It PCM, Or Isn’t It? – PS Audio](https://www.psaudio.com/blogs/copper/dsd-is-it-pcm-or-isn-t-it)
I can also recommend all of his Quibbles and Bits column essays.
---
### Author:  [@dvorak](https://forum.psaudio.com/u/dvorak)
#### Post date: [April 6, 2024, 4:02am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/6 "2024-04-06T04:02:29Z")
That article is what it sounds like when an actual expert says the thing I’ve been clumsily trying to get across! Love it.
Anybody trying to get their heads around DSD please read what Ted just linked to and then feel free to follow up with questions.
---
### Author:  [@Elk](https://forum.psaudio.com/u/Elk)
#### Post date: [April 6, 2024, 4:03am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/7 "2024-04-06T04:03:53Z")
An excellent read
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### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 6, 2024, 6:16am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/8 "2024-04-06T06:16:05Z")
> [@dvorak](#):
>
> A very solid effort, and I love the spirit of sharing 👍
Thank you! Kind words indeed!
I figured if I had these questions, there has to be others with the same or similar, as well…
And I love your “Magic” summary. I added it to the original post.
Thank you, for that too!
---
### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 6, 2024, 6:17am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/9 "2024-04-06T06:17:10Z")
Thank you for this!
I added to the links in the original post.
---
### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 6, 2024, 6:20am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/10 "2024-04-06T06:20:35Z")
This one came up in my feed.
From February 27, 2014. Over ten years ago!
The origins of Ted ? 😃
[ ](https://www.youtube.com/watch?v=vl1zoFJYdUo)
---
### Author:  [@tedsmith](https://forum.psaudio.com/u/tedsmith)
#### Post date: [April 6, 2024, 6:51am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/11 "2024-04-06T06:51:30Z")
This is the board they were talking about:
---
### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 6, 2024, 6:55am UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/12 "2024-04-06T06:55:26Z")
Gus said something about briefcase size, yes?
What are the dimensions?
---
### Author:  [@tedsmith](https://forum.psaudio.com/u/tedsmith)
#### Post date: [April 6, 2024, 3:13pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/15 "2024-04-06T15:13:47Z")
# Board statistics
Number of copper layers: 6
Board outline(s) extent: X = 455 MM; Y = 330 MM (18" x 13")
Number of parts: 1471
Number of pins: 5284 (258 through-hole, 5026 SMT)
Number of vias: 3205
Number of holes: 3463
Three boards cost: approx $4900 parts, (which includes $1100 in audio transformers and $1200 for the custom VCXOs) and $4800 for boards and assembly.
[Edit: I had the wrong report the first time.]
---
### Author:  [@tedsmith](https://forum.psaudio.com/u/tedsmith)
#### Post date: [April 6, 2024, 3:24pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/16 "2024-04-06T15:24:36Z")
Here are some pictures of our meeting with Gus:
Paul and his wife were going out for date night so he came in the next morning:
---
### Author:  [@mrcandude](https://forum.psaudio.com/u/mrcandude)
#### Post date: [April 6, 2024, 3:28pm UTC](https://forum.psaudio.com/t/dsd-for-dummies/37154/17 "2024-04-06T15:28:00Z")
First pic you get a good sense of the size of the board. Whoa!