Pro-Ject Pre Box S2 Digital


(Philo Melos) #746

Have a strange problem with this little thing. Can’t run it in exclusive mode when using asiodriver… The option isn’t there at all. With wasapi it is there, but I prefer asiodriver. Is this common, or is there something faulty in my setup?


(Sean) #747

Hi Philo,

That’s normal with ASIO… ASIO is essentially always in ‘exclusive mode’, so there’s no option for a more exclusive mode.

Sounds like everything is working fine for you with ASIO, so you can sit back and relax :wink:


(Philo Melos) #748

Thnx. Sometimes when I play dsd albums I only hear a hiss. Must pull out the usb-cable a couple of times, or shut off power completely before it works normal again. Thought it might have to do with no exlusive mode, cause it will work with wasapi.
Good to know it’s normal for Asio.
Can’t repeat the dsd thing, everything normal working again for now.


(Rune) #749

Could it be when you play a DSD track after a PCM track?
What if you just upsample everything to either DSD or PCM do you still get the hiss?


(Sean) #750

No worries at all. The advice I’ve had from a few USB DAC designers is always use ASIO in the first instance, if it’s available - unless you have issues with it, in which case you then have the option of WASAPI in Exclusive Mode.


(Philo Melos) #751

Unfortunately I can’t reproduce this fault. Looks like it happens random. This morning all was okay. When it happens again I will try to look more precise at the circumstances.


(Geoff Mirelowitz) #752

I have been using an S2 for several weeks (first a loaner from a local dealer before my purchase – so two different units) and I am confused by some of the comments above.

Under “MQA Capabilities” my Project Pre Box S2 Digital shows “Decoder and Renderer.” I have never had a single drop out. Unless you are talking about the fact that VERY infrequently (once every few days) the music may stop playing. When that happens I just click the play icon in Roon (either on my core iMac or on my iPhone controlling the endpoint) and the music resumes.

I am also confused about the references to “Exclusive Mode.” I am unable to find that in my Roon settings. I believe the reason is I am using a microRendu in conjunction with the Pro-Ject S2, as an endpoint. Am I correct that the microRendu takes care of that without any extra setting necessary in Roon?

Thanks for any clarification anyone can offer.


(Sean) #753

Hi again Geoff, yes the discussion of ASIO vs WASAPI above only applies to Windows for this DAC. There’s no ASIO driver for Mac for this DAC.

For the Rendu, none of that Exclusive Mode discussion applies - the Rendu always has the DAC exclusively so you don’t need to worry at all.

Hope that helps.


(Geoff Mirelowitz) #754

Thanks Sean. But what about the issue of “dropout”? I use the Pro-Ject as a decoder and renderer without experiencing that problem.

Is that what the reference is about to

Or is dropout a separate issue? And again, I’m not experiencing it (to my knowledge) even though Roon is not doing the first MQA unfold for me.


(Sean) #755

Do you ever see MQB on your DAC’s display or is it always MQA shown?

As I mentioned earlier, some people have reported issues when this DAC is doing the FULL MQA decode (MQA on the display). That issue is solved by MQB mode. Note this applies to some people, not all people.

But if you don’t have any serious issues you have nothing to stress about. It only applies to those having issues, not everyone.

Hope that helps.


(Geoff Mirelowitz) #756

To the best of my knowledge I only see “MQA” in the display. As I said, my MQA playback on the Pro-Ject has been basically flawless.

Thanks for the help!


(Sean) #757

As above, some people have issues with MQA with this DAC - not all. If you don’t, there’s nothing to get stressed about.

If you do, in Roon switch to “Renderer only” mode and you wil see MQB on the DAC’s display and this MQA dropout issue disappears.


(Geoff Mirelowitz) #758

By “dropout” do I assume correctly you mean the music skips? In other words some notes do not play but the music does not stop completely?

If so, I’ve had none of that so I guess I am one of the lucky ones. I did check to make sure my unit has the latest firmware update and it does.


(Sean) #759

Yes, anything unusual with MQA playback. If you ever get it, you have the solution above. Until then, enjoy the choones :slight_smile:


(Magnus) #760

I let Roon do the first unfold, and then upsample to DSD128 (both non-MQA and MQA). So my S2 gets DSD128 no matter what I play. Sounds better (in my opinion) than vanilla MQA, and whatever MQA problems you have is gone.

My S2 don’t have any problem with normal MQA though, except a slight transition phase. But with the above solution, that is also gone.


(Bram Tullemans) #761

Hi all,

Can anybody confirm if there is a delay between toslink and rca out? I would like to the Pfo-Ject Pre Box S2 also for my TV out and cannot use lip sync issues in this scenario.


(Sean) #762

I’ve used it like this and never noticed any delay that annoyed me enough to adjust any settings.


(PR Terhorst) #763

Has anyone figured out the differences on the filter settings? I am confused about what each one does, and It’s not easy to hear any differences. They are listed as:
Optimal transient (Pro-Ject preferred)
Fast Roll off (Linear phase)
Slow Roll off (Linear phase)
Minimum Phase Fast
Minimum Phase Slow
Linear Apodizing
Hybrid Filter
Brickwall Filter

I contacted the Pro-Ject distributor, Sumiko, and all they could tell me was the settings are on the chip level and ESS does not provide the detailed information about each setting, i.e. they they are proprietary to ESS.


(Geoff Mirelowitz) #764

Most of the reviews I’ve read suggest that the reviewers have not been able to identify significant differences in these filters. I just use the one Pro-Ject says is preferred.


(Rene Bouwmeester) #765

Some info about filter characteristics:

https://www.avsforum.com/forum/149-blu-ray-players/2821841-official-oppo-udp-205-uhd-blu-ray-player-owner-s-thread-23.html#post52816673

This document has some info about ESS filters (page 9):

http://www.audiodesignguide.com/DACES9038PRO/Manual%20Kit%20%20ES9038PRO%20DAC+%20%20Controle.pdf