Pro-Ject Pre Box S2 Digital: MQA HW decoding at reasonable cost

[bhobba]

21 minutes ago, mansr said:

A spline is a piecewise polynomial interpolation. A FIR filter is something different. Whereas splines of order 0 or 1 are trivially expressed as FIR filters, higher order splines are not.

 

I know exactly what splines are - they are widely used in applied math.

 

Ok lets take a look at polynomial interpolation - they are FIR:

https://www.dsprelated.com/freebooks/pasp/Lagrange_Interpolation.html

 

Now I haven't seen anything similar for spine interpolation, so I cant be sure in a mathematical sense if its FIR or not, however since the claim of MQA is to reduce time smear as much as possible I cant see how it can be anything but FIR.

 

I frequent a science forum that has some pretty high powered professors etc that post there - I will see what they say and get back.

 

Thanks

Bill

 

 

 

[rickca]

All this discussion of filters belongs in a different thread, please.

[bhobba]

3 minutes ago, rickca said:

All this discussion of filters belongs in a different thread, please.

 

I will start a new thread with what I find.

 

Thanks

Bill

[mansr]

13 minutes ago, bhobba said:

I know exactly what splines are - they are widely used in applied math.

I didn't mean to imply that you didn't.

 

13 minutes ago, bhobba said:

Ok lets take a look at polynomial interpolation - they are FIR:

https://www.dsprelated.com/freebooks/pasp/Lagrange_Interpolation.html

 

Now I haven't seen anything similar for spine interpolation, so I cant be sure in a mathematical sense if its FIR or not, however since the claim of MQA is to reduce time smear as much as possible I cant see how it can be anything but FIR.

 

I frequent a science forum that has some pretty high powered professors etc that post there - I will see what they say and get back.

These papers seem relevant:

http://bigwww.epfl.ch/publications/unser9301.pdf

http://bigwww.epfl.ch/publications/unser9302.pdf

[Miska]

2 hours ago, bhobba said:

Ok lets take a look at polynomial interpolation - they are FIR:

https://www.dsprelated.com/freebooks/pasp/Lagrange_Interpolation.html

 

Now I haven't seen anything similar for spine interpolation, so I cant be sure in a mathematical sense if its FIR or not, however since the claim of MQA is to reduce time smear as much as possible I cant see how it can be anything but FIR.

 

I have two different spline interpolators in HQPlayer. IMO, the "polynomial2" is the better one. And IIRC, Wadia also used spline in their DACs. I have Lagrange too, but I don't think it fits these use cases at all, I've only used it to interpolate spectrogram plots.

 

I personally don't like such because of the poor stop-band attenuation. Time domain of course looks nice.

 

One can of course create discrete time sampled version (FIR) of those functions just like for IIR too. As long as function can be applied as convolution, it can converted to a FIR.

 

[Narbooty]

Finally arrived today! Initial impression is positive. Gonna take some time with it today!

[arcman]

Audio Advisor over here in the US has it now http://www.audioadvisor.com/prodinfo.asp?number=PRPRBS2D and Amazon ( I believe Audio Advisor is still the retail outlet).

[left channel]

53 minutes ago, arcman said:

Audio Advisor over here in the US has it now http://www.audioadvisor.com/prodinfo.asp?number=PRPRBS2D and Amazon ( I believe Audio Advisor is still the retail outlet).

 

Thanks for the link! Yes I also found them on Amazon: https://www.amazon.com/s/ref=nb_sb_noss?url=search...

 

I worry they don't have a firmware update installed. Last week Pro-Ject support told me they still don't have the final release.

[arcman]

7 hours ago, left channel said:

 

Thanks for the link! Yes I also found them on Amazon: https://www.amazon.com/s/ref=nb_sb_noss?url=search...

 

I worry they don't have a firmware update installed. Last week Pro-Ject support told me they still don't have the final release.

You are probably right. For many who do not read forums or keep up with such, it could mean quite a few returns if they notice lots of clicking. Hopefully the an update will get posted on their website soon. 

[Samuel T Cogley]

8 hours ago, left channel said:

 

Thanks for the link! Yes I also found them on Amazon: https://www.amazon.com/s/ref=nb_sb_noss?url=search...

 

I worry they don't have a firmware update installed. Last week Pro-Ject support told me they still don't have the final release.

 

Hopefully, people that are purchasing this understand that it's a bleeding edge unit.  With availability on Audio Advisor, it pretty much just arrived in the U.S. for purchase (like a day or two ago).

 

I have high hopes for this DAC.  But I think I'll wait until 2018 to look again and gauge the user satisfaction index.

[MagnusH]

Official firmware available from: http://www.box-designs.com/main.php?prod=preboxs2digital&cat=s2-line&lang=en

Testing it now and seems to work good.

[left channel]

Thanks @MagnusH, the Pro-Ject support manager emailed it to me as well.

I was unable to make their new firmware update utility run, possibly because it must be extracted to a specific location. I was able to do the update using the Pro-Ject Windows control panel I already have installed. Seems to be running well now.

 

The firmware update instructions need some work too. I have replied to the Pro-Ject support manager with some suggestions. Also the user manual and DSD instructions are still incorrect. I will add this new update to my Dropbox folder and continue to distribute it with the user manual corrections.

[Nihilnisibene]

I tried the update right now as well on a Windows 10 computer and could not get it to work. Was just asked how I wanted to open bin.files. Mostly Mac user. Windows s...s.

[exdmd]

Looking forward to a comparison with the Brooklyn DAC+.

[left channel]

2 hours ago, Nihilnisibene said:

I tried the update right now as well on a Windows 10 computer and could not get it to work. Was just asked how I wanted to open bin.files. Mostly Mac user. Windows s...s.

 

You need to first install the Pro-Ject driver and control panel in Windows, then run the firmware update feature from the control panel. I will send you a with a link to all the necessary files and instructions.  I even edited their update PDF to remove the pages that will confuse people.

[GUTB]

Thanks for the alert. Purchased. Let’s see what this baby DAC can do.

[left channel]

@GUTB these probably do not have the latest firmware, and the user manual still has issues. I will PM you a link to my folder containing the update and other resources.

 

All, there is an ongoing discussion and impressions thread here:

 

 

[asdf1000]

3 hours ago, left channel said:

 

You need to first install the Pro-Ject driver and control panel in Windows, then run the firmware update feature from the control panel. I will send you a with a link to all the necessary files and instructions.  I even edited their update PDF to remove the pages that will confuse people.

 

Hi left channel

 

In your discussions so far with Pro-Ject Support, have they indicated a plan for Mac software, for firmware upgrades?

 

 

[Narbooty]

Firmware updated with no issues, working well. I never experienced any of the other problems before though.

 

I love this thing btw. I basically haven't turned it off while home since I got it. I only use tidal so I can't speak for much else, but this thing seems to perform well in every metric. I own very little "hi-res" music, so the mqa ability is a huge bonus. MQA on tidal sounds pretty darn good with this thing. I had tried it using a dragonfly v1.2 and just done the in application initial unfold and actually preferred the "lossless" files over masters/mqa in most cases...NOT the case with this at all. 

[wushuliu]

14 hours ago, beerandmusic said:

At price point i expected.....good job Pro-ject !

...sets a new bar in price for a dual es9038 mono/mono architecture,  w/galvanic isolation, DSD & MQA.

 

https://www.amazon.com/Pro-Ject-Pre-Box-S2-Digital/dp/B073WCRZ79

 

This is why I tell people not to spend big on DACs. The turnaround cycle gets faster and faster every day. Less than a year ago a dual Es9038 would set you back what...a $1000? And Pro-ject is not exactly a cutting edge company. If this unit costs 399 you can bet it can be sold for a lot less. 

[left channel]

3 hours ago, wushuliu said:

 

This is why I tell people not to spend big on DACs. The turnaround cycle gets faster and faster every day. Less than a year ago a dual Es9038 would set you back what...a $1000? And Pro-ject is not exactly a cutting edge company. If this unit costs 399 you can bet it can be sold for a lot less. 

 

Pro-Ject engaged a fairly cutting-edge designer to create this new product generation: John Westlake. You'll find more information about this one in the existing 14-page thread.

[left channel]

4 hours ago, Em2016 said:

 

Hi left channel

 

In your discussions so far with Pro-Ject Support, have they indicated a plan for Mac software, for firmware upgrades?

 

 

 

They have not given even the slightest indication of such a plan, sorry.

 

[asdf1000]

2 minutes ago, left channel said:

 

They have not given even the slightest indication of such a plan, sorry.

 

 

Oh no. Had you asked them already?

 

If not, since you have quick responses from them so far, could you kindly ask the question?

 

On behalf of us Mac users - please 

 

[left channel]

@Em2016 OK in my next go-round I'll ask, although I think I really blew the guy's mind with my firmware utility bug report and instruction sheet proofreading today. But I can already tell you that (a) on Macs their products are supported by built-in drivers, so developing for Mac OS would be new or rare for them, (b) their general policy is to rely on local dealers to help you with firmware updates, so this entire situation is unusual, and (c) the all-out effort to update this product has also been very unusual, and required extra unpaid work by the lead designer who is not a direct Pro-Ject employee. So, I seriously doubt they're going to pay another outside dev to make a Mac firmware upgrader. But I'll ask.

[asdf1000]

1 minute ago, left channel said:

@Em2016 OK in my next go-round I'll ask, although I think I really blew the guy's mind with my firmware utility bug report and instruction sheet proofreading today. But I can already tell you that

 

Ha! You can only do what you can do. Can't ask for more than asking the question. Sincerely appreciated 

 

And congrats on your amazing work with feedback to their Support team. It's helping Pro-Ject and the current end users and potential future end users!