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.

Of course filters influence the sound of oversampling DACs. But filter algorithms in all DACs are all built around common standards with a finite list of variables they can play around with, and there’s nothing particularly innovative or earth-shattering between one DAC manufacturer’s vs another’s. In the case of brands that share the same DAC chipset (such as an ES9039pro), they’re all defined by the options hard coded into the chip, and are just given different names.

Regardless, there’s certainly nothing about PS Audio’s filters that are any different from those offered in other DACs, and there’s definitely nothing magical about them that warrants a $6,000 price tag. Anyway, the discussion of filter options is not germane to my point about the myths of IIS being an allegedly superior digital audio transport or about the outrageous price points given to these “boutique” DACs that don’t measure any differently than a cheap delta sigma SMSL 400ES or a Topping d90se. In fact the affordable DS DACs of the past few years measure demonstrably better than the offerings from the likes of PS Audio and Chord, and they absolutely trounce the measurements of archaic, pricey R2R ladder options.

This phenomenon isn’t something that leads to any subjective differences in sound quality that would convince the acolytes away from the high dollar boutique brands, because we reached the limits of the human ear years ago with digital to analog conversion. An eight year old Chord DAVE sounds every bit as good as a Topping d90se because the Topping’s superior distortion scores and noise floors are not audible (to this point, even though I somewhat hypocritically demand DACs capable of PCM 768 and DSD 512 personally, anything above a SINAD of 96 or a shade above 16 bit is completely inaudible, and the human ear has been proven to be incapable of discerning resolutions much higher than Red Book CDs).

So in spite of the fact that we’ve scientifically proven that advances in digital technology have now allowed mass production of DACs that provide the highest possible audio reproduction that can be achieved, outfits like PS Audio are going to keep writing ever more inscrutable and technologically advanced-sounding one sheets that will keep convincing their customers to shell out wads of cash for the “latest” in DAC technology, despite the fact that the technology reached its finite limits in the last decade and there’s no place left to go.

The future of the audiophile industry, when it comes to DACs, is wholly dependent on cognitive bias and the reliable consumer base that is psychologically held captive to the myth that high cost correlates with quality. Given that DACs are nothing more than computers, why else would otherwise sensible folks still shell out $14,000 for a Chord DAVE in 2023, when the the device’s tech is almost nine years old? Think about other digital devices with nine year old tech—2014’s cell phones, computers, televisions, etc, and ask yourself whether you’d pay ultra premium prices for one of THOSE. 2023 prices for the iPhone 6–take a moment and just think about the motives of ritzy audio manufacturers vs common sense, for the sake of your wallet if nothing else!

I agree with Paul McGowan that DSD is superior to PCM. Part of the reason is that when DSD hits a DAC it doesn't go through filters like PCM does. One of the reasons why a 24/192 recording sounds even better when transferred to DSD to make an SACD. Chandos even has a recording of Symphonie Fantastique that was recorded at 32/352.8 and then transferred to DSD64 for the SACD. And there's another way to listen to DSD off SACDs - take the HDMI out of a universal player (Oppo, Sony. Reavon...) to a GeerFab Audio D.BOB, which legally extracts the DSD and hi-res PCM and outputs over coax to a DAC that accepts DoP over coax (Mytek, Benchmark, Chord, Topping...). (Disclaimer - I'm the inventor of the D.BOB.) Upsampling - I use an iFi Audio Pro iDSD to upsample Internet radio and CDs to DSD1024. Breathed much needed new life into my CD collection. Not quite SACD quality, but a whole lot better than CD.

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.  

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.