Upsampling to DSD in advance

My Mac Mini doesn’t seem to keep up with the real-time conversion to DSD128, and would occasionally choke up. It has no problem to playback native DSD, however.
So, I figured I will just convert my Library to DSD and get it over with.
Any ideas how I can do it? I understand that I need the sox cli, but the options there are very hard to understand.
My sources are mostly PCF AIF files, either in 16bit/44khz or 24bit/96khz.

I would like to upsample to the following specs:

Bandwidth (% Nyquist) 95
Filter Max Length 30000
Filter Antialiasing 100
Filter phase 0
DSD Sigma-Delta Modulator Filter Type: C
Safe volume reduction: none


I don’t think it’s a good idea to upsample offline to DSD128 as you’ll need a lot of space
For example: if a flac 44.1/16 track is 7mb the corresponding DSD128 track will be 403mb (x57 !!!)
Read here for reference
How much ram is installed on your Mac mini and which processor does it have?
Try to reduce Audirvana max memory allocated to 1024/2048
… upsampling to dsd is a very demanding task …

That’s the thing, storage is cheap, computing power is not. I can easily attach an 8tb drive to my mac mini.

I have a late 2012 Mac Mini with 2.3ghz quad-core i7 and 4Gb or RAM. And even that is not enough.

What’s the reason behind reducing the available memory to Audirvana? I assumed more RAM means better performance, but I might be missing something.

Mine is a MacBook Pro i7/16GB ram late 2011 and I can upsample happily only flac 44.1/16 up to dsd64.
And things go worst upsampling if the original resolution grows (96-192) …
In this (old) thread you could find some suggestions to offline upsampling

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You can do that using command line SoX. Check the product website for prepackaged installs.

Another idea could be to use Audirvana as library manager and HQPlayer as “on-the-fly” upsampler “engine”
Assuming that you have a 1tb library and you decide to convert to DSD128 the whole library you’ll need at least 50tb of disk space, a huge investment even if hdd are quite cheap.
To upsample to DSD128 you need HQPlayer Embedded installed on a Nuc10i7 at least, it acts as an upnp device then available to Audirvana.
You need also a little device (a network connected raspberry can do this job) with HQPlayer NAA installed.
The dac will be connected to HQPlayer NAA.
HQPlayer is a very specialized sw developed just for upsampling.
The total expenditure for this setup will be less than $1000.

It’s quite contorted setup you’re proposing. He would be better off just getting a newer Mac.

… maybe not so linear but effective and more or less the half the cost of a new Mac and the half the cost of a 50tb nas (backup not evaluated)

I was thinking more along the lines of a used Mac Mini. If he get’s a NUC PC, he could also just switch to run Audirvana on it.

I still think it’s crazy to invest money just to upsample, it would be better spent optimising the playback setup, room treatment if you use speakers, maybe some better cables… Still, we all know how neurotic audiophiles are, so who am I to judge you.

That’s the easiest solution (!!!) and the cheapest one … even if I “don’t like” Windows…

I don’t have a terabyte of audio, my PCM folder is currently only 70gb. That would become around 4tb which is reasonable.

Converted a sample album with XLD using DSD128 conversion (setting 8), sounds very good but I don’t find it as good as Audirvana. I don’t seem to have the option to tweak the settings in XLD to my liking.

I wish there was a cheat sheet for the sox CLI, it seems very hard to understand how to easily convert any PCM input to the same target DSD settings.

Which NUC would guarantee decent playback? My current 2.3ghz x 4 cores i7 (8 threads) is not bad, how much better can I get? Intel didn’t quite make amazing progress in recent years.

The cpu benchmark score for Mac mini i7 2012 is
Single core 666
Multi core 2620
For Nuc10i7 (up to 4.7ghz 6 core/12 threads)
Single core 1154
Multi core 5850


I’m currently trying the following tweaks, wonder if it will make a difference:

  1. Disable spotlight indexing:

    sudo launchctl unload -w /System/Library/LaunchDaemons/

  2. Disable swap/paging:
    sudo launchctl unload -w /System/Library/LaunchDaemons/

  3. Set Audirvana+ memory usage at 1.5gb.

Will report if it makes any difference. My CPU seems to remain at the 280% even when upsampling sources that are 24 bit / 172khz to DSD128 at the moment.

You might take a look at the manual pages for SoX here…

And this might help get you going too…

I have similarly-configured late-2012 Mac Mini, with 16GB of RAM. There were playback dropouts when converting hi-res PCM files to DSD128. I now use Poikosoft EZ CD Converter to do offline conversion of hi-res PCM albums to DSD64 and DSD128. There are a couple of filter choices in EZ CD Converter, and the program uses SoX, but you cannot control all the SoX parameters as outlined in your post. You might want to experiment with the trial version of the program. I also keep a terminal window shortcut on the Mini’s desktop so that I can run the “sudo purge” command to clear the cache. The 2012 Mini does not appear to have sufficient processing speed to manage on-the-fly PCM to DSD128 conversion.

Thanks for the tip.
I should point out that after applying the settings above, dropouts rarely occurred. I really think this was more of an I/O thing than a CPU problem because I never saw it above 280%.

Ummm… You only possibly get 100% for a CPU… And if you did you would probably fry your CPU… I would imagine 280% would mean you are 180% over subscribed… Or to put it another way, lacking… You can’t store up unused CPU cycles in a mayonnaise jar to use later…

Thanks not how it’s reported for multi-core CPUs. Each core is 100% max. A quad core CPU would be listed as 400% max. So I’m way below the max capacity.