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

[arcman]

Any word yet on A firmware update?

[gahabana]

48 minutes ago, arcman said:

Any word yet on A firmware update?

yes. 

the words are 'little bit of patience'. John Westlake figured out DSD channel swap issue that was easy to fix as well as master sample rate click so i expect it will be out soon. my guess is it will take couple of weeks ...if you have preamp after dac clicks won't bug you much ...

[left channel]

John is working directly with ESS on the "pop" sound, which is caused by a bug in the DAC chip itself. We can help get this work completed by reporting the problem directly to Pro-Ject. Here is their contact form: http://www.box-designs.com/main.php?info=kontakt&cat=default&lang=en

To reach Pro-Ject directly instead of a local distributor, I had to set my country to "Bermuda" on their contact form. But I then entered my true state and country in the City field, and explained in my message along with a description of what I am hearing: a "pop" or "click" every time the sample rate changes between multiples of 44.1 and multiples of 48 kHz.

I am no longer using my S2 product while waiting for a firmware update that will fix this annoying sound.

[gahabana]

hi @left_channel, 

ive just done the same (Bermuda as a country) ... maybe they will respond and if not at least we will know what policy Pro-Ject has around customers.

[MagnusH]

They will be surprised about the number of customers in Bermuda :-)

[left channel]

All  S2 early adopters deserve a vacation in Bermuda. :-)

I've received a response from Pro-Ject already! It includes no bemusement re Bermuda, thanks me for my message, and assures me that "We're working on this issue. So far it seems like an ESS bug, hopefully it can be resolved by a firmware update."

More reports will help ensure John and his team get support from Pro-Ject for this work. Over on pinkfishmedia @MagnusH is also reporting a DSD issue, and has already received a beta firmware update to test. I am impressed with their response.

[MagnusH]

I have tested the new beta and its a great improvement, no loud cracks when switching sample rates, and PCM/DSD channels are correct. 

[arcman]

Thats good to hear. Hopefully, it will pass and get posted soon. The S2 really is a nice component. I’d be surprised if TAS or SP does a review. It will be interesting when someone compares the S2 MQA sound quality to a Mytek mqa Dac. I believe John mentioned a “fixed” volume option in the menu as well. I believe most would use the S2 as a dac instead of a preamp

[MagnusH]

Checked the menu but could not see any fixed line out option, but the volume is digital so if you put it at 0 dB you would have normal line out. But it should also be very easy to add to the firmware.

 

I am surprised about the lack of reviews, but maybe the Pro-Ject hasn't sent out any to reviewers, or maybe it has to do with the later launch in NA. I am also looking forward to some comparisons with other DACs in the same price range.

 

With the new firmware its an excellent DAC though, no question about that. And as far as I can tell, it sounds very good (my previous dac was DragonFly Red but it crushes that one, which sounds very flat and boring in comparison).

[Miska]

9 hours ago, MagnusH said:

I am surprised about the lack of reviews, but maybe the Pro-Ject hasn't sent out any to reviewers, or maybe it has to do with the later launch in NA. I am also looking forward to some comparisons with other DACs in the same price range.

 

IIRC, it has been reviewed in UK's HifiNews and also here in Finland local Hifimaailma. Probably some others too, otherwise it wouldn't have gotten EISA award.

 

[franz159]

9 minutes ago, Miska said:

 

IIRC, it has been reviewed in UK's HifiNews and also here in Finland local Hifimaailma. Probably some others too, otherwise it wouldn't have gotten EISA award.

 

In Italy it was reviewed back in  July by a well known magazine (Audio Review): this is where I read about it when I started this thread.

[arcman]

Does the mqa logo light up on the s2 or is what im seeing online just for marketing purposes? I have my bluesound node set up for outboard mqa dac. 

[MagnusH]

Sure, when it plays MQA it shows the symbol and the sample rate of the fully unfolded music. Remember to remove all DSP though before the DAC, or the MQA information is lost (this includes volume leveling). This has nothing to do with the S2 DAC though, just the way MQA works, it needs data to be bit-perfect.

[Miska]

2 hours ago, MagnusH said:

Sure, when it plays MQA it shows the symbol and the sample rate of the fully unfolded music. Remember to remove all DSP though before the DAC, or the MQA information is lost (this includes volume leveling). This has nothing to do with the S2 DAC though, just the way MQA works, it needs data to be bit-perfect.

 

Or just let for example Tidal application do the MQA decoding and let the DAC do proper filtering instead. The end result is much better that way...

 

[arcman]

2 hours ago, MagnusH said:

Sure, when it plays MQA it shows the symbol and the sample rate of the fully unfolded music. Remember to remove all DSP though before the DAC, or the MQA information is lost (this includes volume leveling). This has nothing to do with the S2 DAC though, just the way MQA works, it needs data to be bit-perfect.

What other dsp?  I turned off tone controls in bluesound app, set for external MQA in bluesound app. I’m on fixed volume in bluesound. Is there something I’m missing?

[MagnusH]

Tidal (or any software) can't do full MQA unfolds, you need the DAC to do the last unfold (or so I have been told).

 

I have no experience with bluesound node, but I know that in order for any DAC to do full MQA unfolding it needs bit-perfect data. Any DSP, volume changes, sending music over bluetooth or anything else that alters the data prevents MQA (I think this is partly because the organization behind MQA don't allow it).

[arcman]

I think theres an issue with s2 and bluesound mqa pass thru.  I cant mqa light to come on oh well

[Miska]

On 10/21/2017 at 12:28 AM, MagnusH said:

Tidal (or any software) can't do full MQA unfolds, you need the DAC to do the last unfold (or so I have been told).

 

"Full unfold" means "upsampling with a crappy filter".

 

So Tidal and other software unfolding does as much as there's to do. Rest of the steps just increase distortion, but don't add any value and are better done with good digital filters instead.

 

[MagnusH]

Its a lot more than just an up-sampling, and as far as I know it does not add any distortion. Still, I would imagine the first unfold is the one that gives the biggest increase in SQ.

[arcman]

I wrote Bluesound letting them know the S2 is not accepting their "unaltered' signal and converting MQA. I did try USB from macbook and Tidal and the MQA logo lights up. John, at Pro-ject, seems to think there is something in the Bluesound Pass thu that is not letting the S2 think it's an unaltered signal. I'll be curious about Bluesound's response (they are really good at responding) since the Bluesound works great with the Mytek and meridian MQA dacs (i've read a few reviews and read Bluesound forum) thru Optical and Coax. 

 

Bluesound will probably say its a Pro-Ject issue. Maybe something in the firmware update will address

[Miska]

8 hours ago, MagnusH said:

Its a lot more than just an up-sampling, and as far as I know it does not add any distortion. Still, I would imagine the first unfold is the one that gives the biggest increase in SQ.

 

At least all the information and measurements gathered so far has been that it is nothing more. MQA doesn't encode more information than 2x the base rate, in addition due to the filter they use there anyway wouldn't be any relevant information produced beyond that.

 

And yes it adds distortion due to poor filters.

 

[MagnusH]

That sounds bad, I thought both unfolds where encoded. Why add the second unfold at all if it does not increase sound quality? Licensing income from DAC manufacturers perhaps.

[left channel]

@MagnusH they say full hardware unfolding beyond the first "MQA Core" is more about optimization for the specific DAC in use. Yet that is also what takes it to 24/192 if available. Personally I have no idea.

Scroll down to the "Full Decoder" graph and caption here:

 

[exdmd]

I can only speak for my setup but in the week I have been using a Brooklyn DAC+ with Tidal if I disable MQA decoding on the DAC+ Tidal only streams 24 bit 48 kHz regardless of Tidal settings. If I want 96 kHz plus I have to enable MQA. The Brooklyn has a Mytek Control Panel application for Windows so you can enable/disable MQA with a mouse click.

[lucretius]

2 hours ago, exdmd said:

I can only speak for my setup but in the week I have been using a Brooklyn DAC+ with Tidal if I disable MQA decoding on the DAC+ Tidal only streams 24 bit 48 kHz regardless of Tidal settings. If I want 96 kHz plus I have to enable MQA. The Brooklyn has a Mytek Control Panel application for Windows so you can enable/disable MQA with a mouse click.

 

In the Tidal app, go to Settings -> Streaming -> Speakers (Brooklyn DAC+) and click on the gear.  Then make sure "Passthrough MQA" is unchecked.