Pro-Ject Pre Box S2 Digital

[Magnus]

If this DAC is fed MQA 1st un-fold at 96k for a 192k MQA file, can the DAC do the 2nd ‘unfold’?

The S2 does both full and last MQA unfolding, and indicates it on the display with different icons.

[dabassgoesboomboom]

The S2 does both full and last MQA unfolding, and indicates it on the display with different icons.

Thanks Magnus! If you get a spare minute, are you able to show 2 pics of the different icons.

Maybe this album as an example if you can, which is available in Tidal in MQA at 353kHz

Many thanks

[Magnus]

I don’t use MQA myself, and no way to test it in Roon anyway, so someone else maybe can do this. But I recall someone describing 2 different symbols for partial/full MQA unfolding.

You can see one of the icons below (picture taken from web):

[dabassgoesboomboom]

No worries, yes I’ve seen that pic before but haven’t seen another symbol, to differentiate from partial unfolding.

I haven’t even seen partial unfolding mentioned for this DAC before, which is why I asked.

Hopefully someone else can help to confirm.

Cheers

[Anthony_Bristol (Anthony)]

I get either a Blue or Green Dot - and also MQA or MQB icons.

edit:

With your Quiet Winter Night album above I get MQA(Blue Dot) - 352k

And in roon:

[dabassgoesboomboom]

With your Quiet Winter Night album above I get MQA(Blue Dot) - 352k

Thanks Anthony.

The only way to test what I’m asking though, for now, is using Audirvana or a Node 2 to do the 1st unfold.

And then see what gets displayed on the DAC display after that, for the rest of the unfolding - i.e. seeing if the DAC display shows further unfolding, using the Quiet Winter Night 353k album as an example.

[Anthony_Bristol (Anthony)]

And then see what gets displayed on the DAC display after that, for the rest of the unfolding - i.e. seeing if the DAC display shows further unfolding, using the Quiet Winter Night 353k album as an example.

Would doing the first unfold in Tidal desktop help?

[dabassgoesboomboom]

Would doing the first unfold in Tidal desktop help?

Oh yes, I forgot about that. As long as Tidal app output is bitperfect, in exclusive mode.

Could you test it out, if it’s not too much trouble.

[Anthony_Bristol (Anthony)]

sure no problem, I’ll update this post with findings

MQA with unfold in Tidal:

MQA Pass through:

[dabassgoesboomboom]

sure no problem, I’ll update this post with findings

Many thanks Anthony

Could you post 2 photos of the DAC display, with the Quiet Winter album.

One photo with Tidal app doing the 1st unfold and another with the DAC doing the full unfold via Roon

Just to see the differences in what’s displayed

[Anthony_Bristol (Anthony)]

Sean, see above.

Edit: Passthrough is same result as direct through Roon.

[Dick_Vliek]

Nice, is that a Rega Elicit-R amp? It’s on my shortlist for a new stereo amp.

[dabassgoesboomboom]

Sean, see above.

Edit: Passthrough is same result as direct through Roon.

Thanks Anthony! Crystal clear now.

The fact that 352k is shown with Tidal doing the 1st unfold (MQB) confirms we’ll be able to do the 1st unfold in Roon Core later and this DAC can do the rest - IF someone wanted to do things this way (choices are nice). Obviously it would still need Roon playback to be bit perfect with all DSP off.

Mostly importantly, that’s a classy looking setup.

[Anthony_Bristol (Anthony)]

Hi Dick, yes it is. Recently upgraded from a Naim Nait 5i. It’s well worth auditioning

[Anthony_Bristol (Anthony)]

Hey Sean, anytime!

If the DAC does all of the unfolding, why do we need to be concerned about Roon doing the first unfold or not? Or is there a benefit to the first unfold in Roon?

[dabassgoesboomboom]

why do we need to be concerned about Roon doing the first unfold or not? Or is there a benefit to the first unfold in Roon?

I haven’t got a clue but my thinking is MAYBE it’s possible the less work the DAC does, maybe SQ improves? Especially if this 1st unfold is the most intensive of the unfolds?

I’m only talking theoretical possibilities. The DAC obviously has the processing power to do ‘the lot’ so there may be no difference in SQ.

You could try it now, with Tidal doing 1st unfold vs pass-through and hearing if there’s a difference, i.e. MQA vs MQB If you can be bothered at some point.

I’d completely understand if you parked it in the ‘I can’t be bothered’ basket

But I live a sad life and probably will be testing MQA vs MQB next week when the S2 DAC arrives, with Audirvana

[Anthony_Bristol (Anthony)]

I haven’t got a clue but my thinking is MAYBE it’s possible the less work the DAC does, maybe SQ improves? Especially if this 1st unfold is the most intensive of the unfolds?

I did have that listen and no, I couldn’t tell the difference. I think the DAC is good to go and you should stop thinking about it and go enjoy a nice beer!

[dabassgoesboomboom]

I did have that listen and no, I couldn’t tell the difference. I think the DAC is good to go and you should stop thinking about it and go enjoy a nice beer!

Ha! You make a very good point

[Magnus]

Hey Sean, anytime!

If the DAC does all of the unfolding, why do we need to be concerned about Roon doing the first unfold or not? Or is there a benefit to the first unfold in Roon?

One advantage would be that you could do DSP after first unfold, for example room correction. Sure, that would prevent the second unfold but the second unfold is just an up-sampling so not that big deal.

I never use MQA on my S2 since room correction is way more important (the SQ gain by MQA is nothing in comparison)

[Anthony_Bristol (Anthony)]

Magnus this is a great point. While I havn’t done RC yet, I am waiting for a UMIK-1 to arrive and send my measurements off to Thierry. I suspect that large TV between my speakers is causing all sorts of mess.

I would like to see Roon automatically enable/disable DSP processing for certain content, ie off for MQA, especially just for upsampling.

Cheers!