If you are an audiophile, you have probably come across this question: Which is better: DSD or PCM?
And if you are just starting to understand high-resolution formats, then you may think that it is like choosing between a petrol and a diesel engine. They both seem to run, but they do it differently.
But in fact, these are not just different ways of storing sound. These are two fundamentally different approaches to how a digital signal is encoded, reproduced and even interpreted by our ears.
Let's figure out what DSD is, how it differs from PCM, why it is needed at all, and does it really provide better sound quality or is it just a marketing story.
1 What is PCM?
PCM is something we've all been familiar with all our lives. It's used in CDs, DVDs, WAV files, FLAC, ALAC, and almost all modern players.
PCM stands for Pulse Code Modulation. It sounds scary, but the gist of it is simple. When you record audio in PCM, your system does two main steps:
- It measures the sound level at regular intervals - this is called sampling rate.
- Each measurement is stored as a number with a certain precision - this is the bit depth.
So if you see "24 bits / 96 kHz", it means that each sample is made with very high precision, and it is done 96 thousand times per second.
PCM is the de facto standard. It works everywhere, all devices understand it, and you can edit it in any sound editor, be it WaveCut Audio Editor or professional Reaper.
Most modern DACs support PCM. They have built-in filters, can work with 16/44, 24/96, and even 32/384. And that's fine. Any headphones, any player, any playback system - everything works.
2 And what is DSD?
DSD is a completely different beast. It stands for Direct Stream Digital, and it was created by Sony and Philips for the SACD (Super Audio CD) format they launched in the late 90s.
Unlike PCM, DSD uses single-bit modulation. That is, instead of recording sound as a series of numbers, it records it as a series of ones and zeros that change at a tremendous rate, for DSD64 that's about 2.8 million samples per second.
Think of rain. PCM is when you catch the raindrops in a glass and measure how many fall every second. DSD is when you simply count whether a drop is falling or not, but you do it so fast that you can accurately convey the picture of the rain.
This recording method allows for a very clean analog output when played back through special DACs, because you don't need to use complex filters like PCM.
DSD comes in several versions:
- DSD64 — basic level, equivalent to 24/96 PCM
- DSD128 — double frequency, less noise in the audible range
- DSD256 — even higher, even less noise
- DSD512 — the highest speed, sometimes it seems like you're listening to a studio master tape
The higher the number, the further the noise moves away from the audible range, and the "cleaner" the output sound becomes. But not everything is smooth here either. Such files take up a lot of space and require powerful equipment for processing.
For correct playback, you need a modern DAC with DSD support. Several well-known models come to mind, such as Schiit Yggdrasil, Oppo UDP-205 or PS Audio DirectStream.
They don't just take a file and play it. They use special signal processing to properly decode this dense data stream. But such equipment is not cheap. We are talking about price tags from $2,000 and up for full DSD playback.
3 Why did DSD appear and what does it solve?
PCM worked well, but it had one problem: sharp frequency distortions at the sampling boundaries. To prevent these distortions from interfering, manufacturers added anti-aliasing filters that "cut" the upper frequencies.
But such filters affect the sound. They can add phase distortions, change the nature of the signal, especially in the high frequency range.
DSD solved this problem differently. It uses a very high sampling frequency, so there is no need for harsh filters. The upper limit of DSD64 is about 100 kHz, and all this without additional suppression.
In theory, this should give a more "live" sound, especially in older systems where bad filters spoiled the sound.
DSD was also interesting because it allowed you to make a digital recording as close to analog as possible. DSD has its own noise inside, but it is shifted to the ultrasonic range, and then it is easily removed by an analog filter at the output.
4 Is there a real difference in quality?
This is the main question for which this whole discussion is started.
Many people like to say that DSD sounds "warmer", "cleaner", "closer to the original". But is it really so?
In terms of measurements, DSD has a good dynamic range and a wide frequency coverage, but with one big minus: in the band above 20 kHz it contains a lot of noise. This is quantization noise, which is difficult to remove without losing quality.
PCM, especially in 24/192 formats, has less noise in the audible range and more predictable behavior at the frequency boundaries.
Now about subjective perception. I had the experience of listening to the same track in DSD64 and in 24/192 PCM. The case was special: high-quality studio recording, high-quality headphones, a good DAC.
Honestly? The difference was noticeable, but not obvious. DSD seemed a little softer, less "digital", especially in vocal tracks. PCM - a little more detailed, especially in instrumental music.
But! If you listen through a regular phone or a budget DAC - you will not hear any difference. Even if the file is in DSD512.
5 Is it possible to edit DSD?
This is where DSD gets its first big delay.
It is almost impossible to edit DSD. Why? Because it is single-bit. That is, you have no depth to change. You are working with a stream of impulses, and if you start editing it, you will get distortions.
That is why the whole process of DSD production looks like this:
- Mixing and mastering are done in PCM.
- Only after that the audio is converted to DSD.
- Sometimes - right on the fly, at the moment of recording on SACD.
This means that there are almost no pure DSD recordings. Most SACD discs are PCM, recoded to DSD.
WaveCut Audio Editor and other popular programs do not support DSD editing. So if you want to change something - first you need to convert to a lossless format. For example, you can convert DSD to FLAC, make the necessary changes, and then convert it back. In this case, some information is lost.
6 Tips from someone who has tried both
Don't chase DSD for the sake of DSD. If you don't have a proper DAC, you won't hear anything.
Check compatibility before buying. Not all players, even expensive ones, play DSD directly. DoP (DSD over PCM) is often required — this is a format that "fools" the DAC into thinking it's PCM. File format does not guarantee quality. A good MP3 recording can sound better than a poorly mixed DSD. Invest in headphones and a DAC rather than in the format. Quality is affected by much more than the encoding type. If you're building an archive, go with PCM. It's easier to manage, has fewer compatibility issues, and you can always convert without losing quality. Don't believe the advertising. Many sellers say that DSD is "the cleanest sound." This is not always true. Sometimes it's just pretty packaging. Try both formats. Listen to the same song in DSD and PCM on the same equipment. You might not hear a difference. Or you might hear a difference, and then you'll know what you like.7 Frequently Asked Questions
What is the difference between DSD and PCM?PCM is a classic multi-bit system that makes many measurements per second. DSD is single-bit, but with a very high sampling rate.
Can my player play DSD?Not necessarily. Check if it supports DSD Native or at least DoP.
Is it possible to convert DSD to PCM?Yes, and this happens all the time. But when converting back, artifacts often appear.
Where can I find DSD tracks?On specialized sites like Blue Coast Records, Native DSD, Primephonic, Linn Records.
Is DSD better than FLAC?Not necessarily. FLAC is PCM in compressed form. And if you listen to it on a good DAC, you may not hear the difference.
Is it possible to listen to DSD on a phone or computer?Theoretically yes, but you will need a special player and OS support. Android and Windows support DSD, macOS - with reservations.
Why do you need DSD at all if PCM is more convenient?Because some people have equipment that handles DSD better. Also, DSD may sound different, and some people like it better.
8 Conclusion
So what to choose? There is no single answer to this question. Technically, DSD and PCM are different technologies. And each has its own strengths and weaknesses.
PCM is a universal, time-tested method. It is suitable for any device, it can be edited, scaled and even streamed without problems. If you want to listen to Hi-Res, but do not want a headache - take PCM in 24/96 or 24/192 format.
DSD may sound interesting, but it is difficult to process, demanding of equipment and does not always give a noticeable gain. If you are an audio enthusiast, you have a suitable DAC and you like to experiment - then DSD will be a great experience.
Choose what works for you. What you really hear and feel. And let the format be just a detail.