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

[matthias]

Has someone compared the Pro-ject to the new Sonore toneDAC?

 

Matt

[Mark Dirac]

15 hours ago, matthias said:

 

Do you know 5V powerbanks with non-switching or without regulators between battery and DC output?

Thanks

 

Matt

Yes. Very easy, cheap and effective:

 

https://www.aliexpress.com/item/4-8V-6V-Battery-Box-With-Switch-4-AA-Batteries-Stack-USB-Battery-Storage-Clip-Holder/32820217325.html

 

This is a simple battery box for four 1.2V NiMH cells, with a USB connector. £2 from AliExpress.

 

The fully-charged voltage is 5.45V, and falls immediately to 5.3V when connected (and under load), which I believe is only slightly above USB voltage specs. Anyway, the S2D doesn't complain or get warm at 5.3V. The box supplies power for about 2 hours using 2900mAh NiMH cells. The S2D misbehaves when the voltage falls to about 4.5V  This is such a cheap solution that I have two. When one runs out, I plug in the other and recharge. 

 

Simple, if inconvenient. No switching. No regulators. No mains noise. No common-mode noise.

[matthias]

14 hours ago, Jud said:

Do you have a Rendu or one of the Regens? They will convert the voltage for you. So will an LPS-1, though that is not an inexpensive power supply compared to some non-ultracap LPSs, for example.

 

Thanks, unfortunately I have neither of them.

 

Matt

[Jud]

3 hours ago, matthias said:

 

Thanks, unfortunately I have neither of them.

 

Matt

 

Then another solution can be less costly for you. 

 

Thanks for the DIY Audio link, I’m curious to have a look.

[Jud]

On 9/24/2017 at 6:19 AM, arcman said:

When using as a dac only, can the volume be switched to fixed?

 

Just turn the volume to 0 dB.

[Jud]

11 hours ago, Mark Dirac said:

Yes. Very easy, cheap and effective:

 

https://www.aliexpress.com/item/4-8V-6V-Battery-Box-With-Switch-4-AA-Batteries-Stack-USB-Battery-Storage-Clip-Holder/32820217325.html

 

This is a simple battery box for four 1.2V NiMH cells, with a USB connector. £2 from AliExpress.

 

The fully-charged voltage is 5.45V, and falls immediately to 5.3V when connected (and under load), which I believe is only slightly above USB voltage specs. Anyway, the S2D doesn't complain or get warm at 5.3V. The box supplies power for about 2 hours using 2900mAh NiMH cells. The S2D misbehaves when the voltage falls to about 4.5V  This is such a cheap solution that I have two. When one runs out, I plug in the other and recharge. 

 

Simple, if inconvenient. No switching. No regulators. No mains noise. No common-mode noise.

 

In another thread discussing power supplies, someone who designs sophisticated digital circuits for a living had this to say about such battery supplies without regulators:

 

 

[Miska]

In a phone, laptop, etc you always have a switching regulator... The analog section chip in S2D uses built-in charge pump to create needed additional negative voltage rail, which is also kind of switching regulator.

 

[asdf1000]

Hi @Miska , i see you're at the Munich Show.

Do you know what this new DAC is about? Is it there at the show?

 

[asdf1000]

Seen it here:

 

https://www.soundandvision.com/content/pro-ject-audio-systems-thinks-beyond-box

 

[asdf1000]

On 4/24/2019 at 5:31 PM, Miska said:

The analog section chip in S2D uses built-in charge pump to create needed additional negative voltage rail, which is also kind of switching regulator

 

[Miska]

On 5/12/2019 at 9:29 AM, Em2016 said:

 

 

He doesn't mention anything about what goes inside the chips...

 

http://www.esstech.com/index.php/en/products/audio-amplifiers/sabre9062q/

 

 

[Miska]

On 5/11/2019 at 11:09 AM, Em2016 said:

Hi @Miska , i see you're at the Munich Show.

Do you know what this new DAC is about? Is it there at the show?

 

 

I didn't notice it there, maybe it was powered down like most of the other Pro-Ject stuff that was just dead boxes on display.

 

Only on Sunday I had time to listen to some systems. Esoteric had pretty good sounding setup and seemed to have now moved to discrete DSD DACs as well instead of COTS DAC chips. On Saturday morning I listened through the demo of the new T+A DAC.

 

[Jumpwire]

Is no one using MQA decoding with this DAC?

 

I based my purchase on this forum and another one. There was an earlier mention of the problem, but it seemed fixed.

 

The problem is NOT fixed in 2.12 Firmware update. The last promised update never came.

 

I am having constant MQA drop outs. 70$ USB Cable and LPS doesn't matter. 

 

There goes 500$. As much as I want to like this product, it feels totally half-baked with its broken MQA decoding.

 

[TomETS]

Tidal MQA works fine for me.  Has problems if I send another audio source to it mistakenly at the same time.  Need to reset things after that.

 

[asdf1000]

9 hours ago, Jumpwire said:

The problem is NOT fixed in 2.12 Firmware update.

 

Correct but you won't see the problem if you have your software perform the 1st unfold. In this mode, you'll see 'MQB' shown on the DAC's display.

 

The bug is only there when the DAC does the full MQA decode. What software are you using?

 

[left channel]

11 hours ago, Jumpwire said:

I am having constant MQA drop outs. 70$ USB Cable and LPS doesn't matter. 

 

1 hour ago, Em2016 said:

 

Correct but you won't see the problem if you have your software perform the 1st unfold. In this mode, you'll see 'MQB' shown on the DAC's display.

 

The bug is only there when the DAC does the full MQA decode. What software are you using?

 

 

2.12 did reduce the number of drop-outs but did not completely solve the problem. This DAC is still known to be more sensitive than most to imperfections in an MQA signal, and for not falling back smoothly to an undecoded format when that happens. Having said that, @Jumpwire your situation seems worse than most and I'd be interested to hear if the above MQB suggestion helps. And a solution for getting full MQA unfolding from your system might be adding a USB clean-up accessory, with options ranging in price from a Jitterbug to a Wyrd to an ISO REGEN.

[Miska]

Many other brands work around the MQA problems by leaving MQA on the data path always with their upsampling filter. And maybe just offering option to disable MQA altogether as alternative to always-MQA path (Mytek).

 

[Jumpwire]

I would like the DAC to do full MQA decoding as its supposed to. I took a look at all three USB clean-up accessories you mentioned, and according to Audio Science Review they seem like snake oil. It seems stupid to keep throwing money at this DAC when most people report these issues without any guaranteed fix. I wonder if the Bluesound Node 2 has the same MQA issues? I might as well sell this thing and add 50$ to get a Node instead of spending another 200$ on another cable and USB plugin.

 

If I had the to burn I would try these products, but at this point it seems like I should just get a better DAC.

I was looking to buy a Pro-ject turntable in the near future, not anymore this company is totally black balled in my books.

 

 

[asdf1000]

7 hours ago, left channel said:

This DAC is still known to be more sensitive than most to imperfections in an MQA signal, and for not falling back smoothly to an undecoded format when that happens.

 

I haven’t seen any reports of people having issues with the DAC in “MQB” mode... ie software does the 1st unfold and the DAC does “the rest” (rendering).

 

One of the software companies that offer the 1st unfold/decode mentioned this solution to me... the bug only shows up when the DAC has to do the full monty.

 

 

[left channel]

1 hour ago, Jumpwire said:

I was looking to buy a Pro-ject turntable in the near future, not anymore this company is totally black balled in my books.

 

They've been making turntables for decades. Computer audio is a relatively new thing for them.

 

 

[Jud]

14 hours ago, Jumpwire said:

I would like the DAC to do full MQA decoding as its supposed to. I took a look at all three USB clean-up accessories you mentioned, and according to Audio Science Review they seem like snake oil. It seems stupid to keep throwing money at this DAC when most people report these issues without any guaranteed fix. I wonder if the Bluesound Node 2 has the same MQA issues? I might as well sell this thing and add 50$ to get a Node instead of spending another 200$ on another cable and USB plugin.

 

If I had the to burn I would try these products, but at this point it seems like I should just get a better DAC.

I was looking to buy a Pro-ject turntable in the near future, not anymore this company is totally black balled in my books.

 

Look at Miska's response in a little more detail. He's telling you getting DACs to keep a lock on MQA input is sufficiently difficult that many manufacturers simply use the MQA filters (which let certain kinds of distortion through - though in most cases it shouldn't be audible) on all content, even non-MQA.  

 

Now this might be desirable for you in order to get reliable MQA performance, but for me, since I don't listen to music processed via MQA, it's not. I think this is less an indication of unreliability on the part of Pro-Ject, and more an indication that they've chosen to make their DAC operate reliably with the bulk of available music.  

 

All that being said, I do understand it's very frustrating to purchase a product that doesn't do the thing it was advertised to do that you bought it for.

[Mark Dirac]

I enjoyed listening to MQA from Tidal without difficulty for months - until I switched to Qobuz. I didn't switch to Qobuz because of bugs affecting MQA playback, but because I became jaded with trying to penetrate the obfuscation surrounding MQA.

 

MQA for me is an extra level of complexity in an already-complex process of reproducing digitally-streamed music well. And MQA the organisation are too duplicitous in their explanations of what's going on. They have made an abstruse technology even more awkward to embrace.

 

So, whilst my comment doesn't assist Jumpwire's with his MQA hassle, I am answering his original question "Is no one using MQA decoding with this DAC?".

[Jumpwire]

On 6/3/2019 at 9:45 AM, Jud said:

 

Look at Miska's response...

 

Thank you for clarifying it for me further. Wish MQA was a seamless experience at this point.

 

After pursuing Pro-Ject on social media I received an official response:

 

Quote

Hi, Of course we are aware of the dropouts. As are many different manufacturers who all have similar problems. The dropouts you are experiencing are MQA format related. Or rather are caused by the MQA encoding and the MQA code, responsible for the hardware unfolding, that is running on the XMOS chip. The MQA code is propriatory and is provided my MQA themselves, custom made for our device. This is why MQA related updates can take much longer to push out than regular firmware updates. The dropouts are highly variable though, and also depend on the song and how it is encoded. What you can try, is to set your playback software to do the first unfold, and then the rest of the unfolding is performed on hardware by the Pre Box S2 Digital (this is when you get the purple dot on the display of the Pre Box S2 Digital). Keep in mind many people do not have these dropout issues at all. It depends on the playback software, operating system and even the song you play on Tidal and its specific MQA encoding. We are working with MQA to get it fixed, as this is is also depending on our chosen hardware solution it can take some time for MQA to account for that and provide a build for us. Hope this information is able to give you a little more insight and we hope to have new firmware soon.

 

Also after much experimenting with Roon and Audirvana, I have come to the conclusion that Audirvana sounds best during the MQA dropout. Instead of having the sound dropout completely like Roon or the Tidal player it introduces a little bit of audible static while it looses decoding.

 

I will be utilizing the MQB workaround while patiently waiting for the next firmware update. Pro-jects response prevented me from selling this DAC right away. I asked if the update is scheduled for release this year and will post the response if any.

 

[Jud]

I don't suppose we could convince you that non-MQA-encoded material (for example, downloads, Qobuz) actually sounds better, eh?  😉

[fgribas]

51 minutes ago, Jud said:

I don't suppose we could convince you that non-MQA-encoded material (for example, downloads, Qobuz) actually sounds better, eh?  😉

 

MQA discussion is a long long story 😄

 

But in a nutshell, MQA is better than redbook when you only do the 1st unfold by software and then upsample with good filters (with HQPlayer for example). Pure MQA (1st unfold + MQA own filter) can sound better than redbook, or the same, or even worse.

 

Qobuz and every other real hi-res source is better than MQA, no doubt about it. I currently have Tidal and Qobuz subscription, both used on Roon. And I'm very happy with it and my S2D.