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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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Showing 1 response by hgeifman

hgeifman
2,113 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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