Roon DSP Sample Rate Conversion settings explained?

I have some time to kill today and am looking at the DSP Sample Rate Conversion settings in Roon. Can anyone explain the myriad of choices starting from the top and if they are needed at all with DSJr?

Sample rate conversion choices

Sample rate conversion settings:

Sample rate conversion filter choices

DSD processing settings:

Sigma-Delta Modulator choices

SDM gain adjustment

Parallelize sigma-delta modulator yes-no

Enable native DSD processing yes-no

DSD to PCM filter choices

DSD to PCM gain choices

The Roon community has detailed explanations of anything Roon and has pretty good search capability. Roon community is accessed easy using the left side drop down and selecting community at the bottom of the drop down.

I do not use SRC, let the PSA DS DAC and Bridge take care of that. I also select the MQA on in the audio device (DAC) setup under show advanced.

With Ted’s Snowmass I prefer his upsampling and do not use Roon sample rate conversion.

There are no absolutes, well don’t try to send higher DSD than the Bridge II (DSD128?) can take but otherwise try out the options. You won’t break anything.

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I have been tinkering around with the various settings today and really don’t know what the settings themselves or the options specifically mean. (precise, minimum phase, 7th order clans, etc.)
These are terms that have no meaning to me. I guess I need to research more.
It appears as though Roon knows the capabilities of the DSJr and doesn’t change anything it doesn’t have to.
If I send a DSD256 file it automatically gets downgraded to DSD128 or DSD64 (I forgot which) on the way to the Jr. I think this must be part of the “Roon ready” certification.

I believe you’re right regarding the Roon Ready certification.

Richard mentioned the Roon Knowledge Base - here’s a direct link to sample rate conversion.

http://kb.roonlabs.com/DSP_Engine:_Sample_Rate_Conversion

Yes, part of Roon cert… I was in the same position a while back and my rational was hell, let PSA work it out. I have yet to have an issue with pops too… however, fun to understand if you are working a stack of tunes on the couch…

Understand, the PSA DAC is built from the ground up w/ Altera FPGA and not a typical DAC chip Roon basis assumptions on…therefore, understanding TS is the man, I trust TS more than Roon… :woozy_face:

Thanks Brett, Xilinx Spartan 6 for this DS DAC. Assume TSS will have a lot more resources. Thought he was using Quartus… Vivado it is…

@cardri Agreed. I’m not having issues of any kind. Just interested in why the settings exist and what the various options might do for the playback.

@brett66 Thanks. I did find that page earlier today. I was also looking for some type of explanation of the choices in the various drop down lists. Probably more out of curiosity than anything else.

This is one of the very few days a year that I don’t have an onerous list of things to do hanging over my head and I do have a long playlist qued up so I thought I would use the time to try to learn something new as well as listen to some music…

I just finished paperwork yesterday so Sunday is a holiday… thought it would have taken entire weekend so boss gave me the day off. Like a soldier on a 3 day pass, not giving a diddle squat…

10-4. Mine are way to complex for me to figure out by myself. I have a really sharp CPA to do the dirty work for me.

I find Wikipedia.org to be most helpful when learning about topics and terms I know very little of. For example, linear and minimum phase; I get lost in the math quickly but it’s good to exercise the brain.

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@brett66 I forgot about my friend Wiki. And I give them a donation every year for the service. Going there now. Thanks!

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I dug up enough stuff on Wiki to keep me reading way past my bedtime. I am surprised that Roon assumes that the user knows what these settings and switches mean as they don’t really explain the options given. Most users must be more familiar with the terms than I am.
Thanks all

Once you’ve landed on the selections you like or don’t like (the sound of) do the definitions really matter beyond the academic understanding of course?

No. Not really. It seems like there would be some type of definition of the terms and what to expect in SQ so there might be a reason to make the particular choice except pure whimsy. I’m always interested in the mechanical / scientific side of art and this is a great place to learn about it.

They made a step in that direction with the addition in 1.6 of this opening blurb (that can’t be closed). It’s hard to please everyone, some want more info others less. I agree with the interest in the science of it but any indication of SQ change would be debated endlessly. None of the choices are wrong and none of them are right. It depends on many variables that Roon authors simply can’t take into account.

Just the Sample Rate Conversion section alone has such a big decision matrix I think I will just leave it Mr Smith as you guys have done. This is some really nice sounding gear.

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Yeah, with an MSEE in DSP… I quickly understood Ted’s contribution to the music and quickly turned off the SRC DSP…:slight_smile:

However, it is good to read up on that stuff if you have a freeday, loaded playlist and Wiki…:blush:

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I don’t own a PS Audio DAC. I listened to one and I liked it very much but I decided to stick to my own Totaldac stack. That said however; The principle of converting PCM to DSD in the digital domain by pure math and smart coding is IMHO a genious concept. To my knowledge PS Audio is the only one doing that in “hard coded” FPGA. To make DSD analog is a just a matter of using the right coffee filter paper. But: Who is going to do that conversion…? Roon or Ted…? In this case I would put my money on Ted…
There’s one catch however: I have the impression that the end result of programming an FPGA is not always the same. More on this in the following thread: Snowmass V1sounds better than Snowmass V2

@ronaldwanders Thanks. It seems as those small “nuance” digital sonic tweaks are indiscernible to these old ears anyway. As I said earlier maybe they were being ignored and not sent to the DAC.
I did end up leaving Parallelize Sigma Delta Modulator = Yes and Enable Native DSD processing = Yes as they made sense to me. Not sure that made a difference but didn’t hurt anything either.
Playing music using my office computer as a Roon endpoint and there are not nearly as many DSP choices so it must also be dependent on the capabilities at the endpoint.

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