Roon Upsampling WTH?

According to Roon, both DSD64 and DSD128 are encapsulated in PCM to the Oppoo over USB. I’m not sure of the mechanics, but the Oppo claims to be receiving DSD64 and DSD128 signals respectively.

Noted, but there’s no benefit in trying that, hence the recommendation to try DSD128 over USB.

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Not outdated for the purpose of explaining the benefits of upsampling to DSD64 vs DSD128 :wink: Which is more relevant to this thread.

But agreed, many other things have advanced since that article was written.

You didn’t change it, but the Oppo is using different filters when dealing with a DSD signal vs. PCM. That might well be audible.

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I have always been confused about upsampling, so have ignored it. Plus I understood that DSP settings could cause some problems for MQA playback.

Could someone tell me what settings I would need to change to try it on my system? I use a microRendu and a Pro-Ject Pre Box S2 Digital. Roon automatically sets my Pro-Ject as a “Decoder and Renderer” for MQA.

If I were to try upsampling what settings would I have to adjust?

Many thanks.

Interesting, but I will say that I’ve tried out every single one of the filters in the Oppo before now, and none of them had a dramatic effect on the sound quality. At best it was subtle.

I used to own Meridian and upsampled via my processor. Several system variables have been changed since then, including the room. In any case, I don’t recall ever been blown away by their apodising upsampling. Roon upsampling has however been transformative for some reason. I don’t get exactly why, but I’m really grateful for it.

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Because of SDM vagaries, PCM and DSD rarely play back at exactly the same levels in otherwise the same signal path. Unless you measure and compensate for those level differences, legitimate qualitative comparisons are not possible.

AJ

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Most modern high performance DACs are multibit. Latest ESS chips have 6 bits. Why would you think there is a benefit from taking 24 bit PCM and converting it to 1 bit. Perhaps conversion to DSD had some kind of logic in the days of 1 bit Delta Sigma DACs but those days are over. DSD has huge amounts of high frequency noise that must be filtered out - so it is adding complexity. Comparatively speaking a 24 bit PCM file is about as good as it gets (granted most of the best electronics can still only provide 21 bit resolution so there are more bits than needed - future proof if you will))

Of course, if you have native DSD files then I would play those directly to a DSD capable DAC. But why convert to DSD files that exist as and were created as PCM files? Are you finding an audible improvement also? DSD256 or DSD512 suggests you have a recent perhaps SOTA DAC - what are you using?

Yes I have noticed this. Volume matching to compare 16 or 24 bit native files against the same file converted to DSD was tricky when I tried it. It almost seemed slightly dependent on the sample rate of the original file to me but I have not conducted rigorous testing. My testing of upsampling to DSD64 on a Benchmark DAC 3 wasn’t thorough but I quickly came to the conclusion that there was no audible difference (results apply with only my gear - not saying others won’t get large differences as it boils down to how their DAC handles the different conversions)

For example DAC Bryston BDA-3 on AK4490 chipset accept DSD for directly conversion to analog signal (w/o conversion to PCM) and PCM for conversion to DSD and then to analog signal inside chipset. So there is a obvious benefit of external PCM -> DSD conversion in Roon Core due to best algoritm and powerful computer vs such conversion inside AK4490 (as and any modern delta-sigma DAC chipset).
Of course if you have multibit DAC (not Delta-Sigma) that there is no sense in an external PCM > DSD conversion because multibit DAC converts the PCM directly to an analog signal.
But now multibit DAC are rare, and only in the upper price range (for example MSB DACs).

Latest ESS chips are all 6 bit and are far from rare…

No matter the tech talk, in my system with a Pro Ject Pre Box S2 Digital there is definitely a difference between PCM and DSD, and I like DSD better (PCM sounds a little harsh and raw in comparison, at least on my speakers).

I will soon update my speakers though (probably to Dynaudio Special 40), we will see what I prefer then.

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The Special Forty are on my wishlist as well, let us know how they sound!

This is so called “multi bit Delta-Sigma” (as all modern delta-sigma DAC) which has nothing to do with a real multi-bit DAC.

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Also considering going passive again, but staying with Dynaudio. What would you power the Special 40 with?

It depends what you define as multi-bit. Since the ESS 9018 has 6 bits then for me it qualifies as multibit. The idea of multi-bit DACs is that it lowers the noise floor over single by DACs. In fact you can see that these latest new ESS chips are basically a hybrid between true single but delta-sigma and a ladder or R-2R DAC. By using 6 bits instead of 16 they still have excellent linearity but by using more than 1 bit they have much lower noise. Basically these new designs are taking the best from both discrete ladder DACs and single bit delta-sigma. There is nothing not real about the six bit capability - it uses a ladder of 64 individual 1 bit steps - all in parallel just like a ladder DAC.

Such is technology and progress.

If I go with Special 40 I would pair them with this, and then maybe upgrade electronics further ahead (my DAC will be preamp):
https://www.xtzsound.eu/product/edge-a2-300

Its cheap but sounds surprisingly good, and has enough power to drive most speakers (although probably not good enough to get all SQ from Special 40).

I’m most defiantly bias since I use the Chord DAVE that, from what I understand, was only gifted DSD playback as a secondary format to please the masses. I hear no benefits from up sampling to DSD (thus far) or up sample PCM for that matter.

On the other hand the DAVE works with onboard filters and upsampling of its own. So I’m not in the camp against upsampling, and I can not say I’m against DSD upsampling on other DACs.

When I got in to this hobby maybe 10 ears ago there were a lot of people still discussing if DACs even could “sound” different. I have electrical engineer friends who still think that’s all in the minds of “audiophiles”. Or one actually kind of changed his mind after I demoed my system with the Dragonfly Red vs the DAVE.

Anyway, if it sounds better go for it. If you want to know why then maybe you’ll find even better implementations. Filter settings or not, experiment and see what happens.

Stay curious, critical and have fun. If you lose one of the three it’s just not the same anymore. :yum:

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This is wildly of topic, but I look forward reading the review on the Xtz edge in next issue of Hifi & Musik. Have you heard it?