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.
128x128classdstreamer

Roon Roc Nuc upsampling to 256 DSD feeding a VMV D2 is not ‘bright or hard’, but smooth and quiet with loads of detail and great separation and layering. Backup vocal singers are beautiful and easy to follow on say a John Gorka selection. The AKM 4499 shines in this configuration. Everything has a palpability, certainly no ‘edge’ running native. Plenty to fiddle about with without going into HQPlayer. PCM can also be very good and once you find a preference it is easy to swap in or out to various resolution from your remote device. Build a Nuc, control what you plug it into, how you feed it, (digital likes isolation, ssd, nice filter caps, ect…) mine does DSD512 also, but consensus seems 256 is the sweet spot. I2S and better clocking thru a DDC, I’m told offer further improvements. Streaming radio, something like ‘Mountain Chill’ out of Telluride, from Roon sounds damn good, as it looks to be upsampled from its lower decent resolution broadcast, then forwarded to the dac. Surprisingly nice sound quality, upsampled from around the world, via live stream. That’s a pretty big plus for Roon…

http://mountainchill.com/

I love DSD.  My Oppo 105 outputs the DSD layer of SACD over HDMI into the HDMI input of my Bryston DAC3.  I also have some DSD downloads but most of my DSD listening is SACD.  

I looked into upsampling with Roon. When I use the computer as Roon Core only (and send the stream to the HiFi), I don’t see the ability to upsample. I do see the ability to upsample when the computer is also acting as the streamer.

Right click on the device at the lower right, select Device Setup, then scroll down and click on Advanced Settings.  Set the maximum sample rate there. 

Then right click on your device again but select DSP.  Second slider will be Sample Rate Conversion.

 

 

When I get a chance to listen critically, I'll post my findings here. I know in the past years casting Qobuz that I notice the difference between 16-bit and 24-bit content. But I haven't picked up on SQ improvements based solely on sample rate. This might be because bit depth variable has always been easier to test for. This will be my first time intentionally isolating sample rate. 

This leads me to another question, how might I go about upscaling the bit depth? (Is "upscaling" the right word here?) I can't easily attach screen shots here to show, but Roon's "sample rate conversion" area only seems to affect the sample rate, not the bit depth.