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Upsampling PCM or DSD in 2022

The purpose of this post is to ask the collective about the best options for upsampling today, and whether it’s worth doing. I stumbled into this topic after recently considering Paul McGowan’s take on DSD, and after reflecting on the upsampling in my home theater system.

Paul believes that DSD is world’s better than PCM. That caught my attention, because, until now, I have been operating under John Darko’s view that high res (i.e. 24-bit and above) is nice but not worth chasing--CD quality is good enough. But audio does seem analogous video. And 1080p isn't good enough for my video streams. So, I now want to give DSD and upsampling a shot.

In my home theater system, I use an Nvidia Shield TV streamer for its AI upsampling, driven by its graphics processor. Plenty of video content is still being released or only available at 1080p. Although upsampled 1080p isn’t as good as 4k, it’s better than basic 1080p. That upsampling makes a big difference for me. I strongly dislike watching 1080p content on my 4k TV. As far as I’m aware, the Nvidia Shield streamer offers the best video upsampling on the market, and it only costs >$200. It occurred to me that I might get similar gratification by upsampling audio too.

Upsampling can be performed at the DAC, streamer, server, or somewhere in between. Here are the major options I’ve considered so far:

  1. PS Audio’s Direct Stream DAC costs 6k. As an FPGA unit, it has lots of extra power that this manufacturer directs towards upsampling, and upsampling PCM to DSD is a major selling point for this device. Unfortunately, you have to get to the Direct Stream in the lineup to experience that feature.
  2. Chord’s Hugo M Scaler costs 5k. Although Chord builds FPGA DACs too, Chord sells a separate component for upscaling. In the audio chain, the M Scaler sits between a streamer and DAC. Because Chord separates out upsampling functionality into its own component, Chord’s solution is likely more expensive than PS Audio’s.
  3. HQ Player software costs >$300. HQ Player is a software service that can be installed on a server, or on a computer that sits between the server and streamer. Besides being affordable, you can pair HQ Player with Roon. The author of AudioBacon reports HQ Player introducing up to 30 seconds of lag to an audio stream when set to the most demanding upsampling algorithm even when used with a powerful Windows computer. But another commenter mentioned that his M1 Apple device introduced zero lag when running HQ Player.

Because the retail price of the components in my stereo system came out to about 5k (when new), HQ Player is where I’m looking for now. Please comment if:

  • You know about some other upsampling options I ought to consider;
  • You have opinions about the value of high res audio or upsampling; or
  • If you have anything you’d like to add to the conversation.
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spkrplus's avatar
spkrplus
64 posts
 

I cannot and shall not have any general conclusion.  I shall say though that HQ Player upscaling all PCM to DSD only using HQ Player author Miska's specific recommended modulator (requires high power dedicated computer) > T+A DAC 200 ($7150 USD SRP) in DSD NOS (non-oversampling) mode rivals any cost no object digital playback system.  I would not be afraid to compare it to a $100k MSB or dCS rack (I heard an $80k MSB rack and the latter.)  

Regardless all the different potential perceptions and preferences experienced listeners may have for DAC A vs. DAC B: I shall say here and now that every single experienced listener employing a decent system or better who AB tested (takes only 20S to switch) PCM (even HR) vs. DSD on this system would prefer the latter every single time and without exception on all music programs.  DSD's advantage in this system is well beyond the pale correlating to different taste.  DSD appears to have 6-10 dB greater dynamic range just to start and no one in a quiet room prefers dynamic compression over the lack of same.  

The primary difference in the above test giving DSD the immeasurable edge every time over any PCM is the fact that all the filtering, modulation and DSP takes place in DSD octaves farther from the audible spectrum than with PCM.  

All bets off if HQ Player is not setup appropriately for DAC 200 or if a different DAC is employed.

Note I love John Darko's advice in general and am NOT contradicting his general advice.  My advice is very specific first hand.  If anyone wants to hear the above described AB test I'm 75 minutes NE of Salt Lake City.  The rest of the system is world class including the room and cables.  

erik_squires
16,253 posts
 

Put me down as a vote of indiference for DSD in 2023.

 

Ag insider logo xs@2x
reg19
82 posts
 

While not crazy expensive, I do have a decent system (MSRP > $100k) with a tube preamp and SS monoblocks.

I find HQP to be the best value for money purchase in my system. BTW: HQP5 is a big upgrade from HQP4 in terms of SQ.

While I would say, in high end (and / or resolving) systems, the benefit is system dependent, a system change can change preference from not using HQP to using it (or vice versa).

Here’s a specific example: recently, with a VAC preamp and Kubala Sosna Fascination speaker cables, I preferred Roon redbook (no HQP). When I changed to KS Elation cables, I prefer using HQP over redbook (Elation, while an upgrade over Fascination, makes my system sound a tad less musical than before. Upsampling to DSD512 using AMSDM7EC 512+fs / Sinc mGA brought back the musicality in spades.

 

 

christianb5s4
237 posts
 

Not DSD or PCM specific, but I've been finding more and more that it's dependent on where the recording comes from which is hard if not impossible to determine via streaming. Some 16bit recordings can sound phenomenal and in some cases, better than 24bit+ versions of the same song/album.

 

This isn't as much an issue if you use physical or local media, of course.

hgeifman
2,259 posts
 

As described above, I understand that both the PS Audio DirectStream Mk2 DAC and HQ Player up sample PCM to DSD. Obviously, some people believe this conversion results in improved sound quality and others do not. I have no DSD listening experience so I do not know. I also understand that the other components in the system, obviously, influence the overall sound quality (as described above). My questions are:

1) Are there other devices that also up sample PCM to DSD? For example, can I purchase a device that accepts PCM out from my Aurender, for example, converts it to DSD for input to my DAC that supports true 1-bit DSD for DSD content? Does this really MAKE sense?

2) How exactly does PCM get converted to DSD? I know the PS Audio DirectStream DAC uses FGPA with custom instructions to make this conversion. I assume a combination of software and hardware are required but, in simple terms, how exactly does this conversion work? How much computing power is required for a PCM to DSDS conversion?

3) Once the PCM stream has been converted to DSD, how does the DSD stream get converted to analog? Does it use a filter to make this conversion? Please explain?

4) The most important question is how does listening to PCM streams compare to listening to a DSD Stream that has been converted by one of the above devices?

5) My current audio system only streams PCM so I am looking for more information on these PCM to DSD conversion options. Thanks.

 
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