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

[Mark Dirac]

Thanks for the links Rica. That's a smart web site that iFi have nowadays. I am afraid I have not experimented with any devices like those. Partly because I trust John Westlake to have done an optimal job for the money, and partly because of my inadequate ears - I cannot hear any difference between:

• power over the signal USB
• power from the supplied wall wart
• power from a linear battery supply (NiMH)

when using LCD3 headphones.

 

I had a quick look at your links, and at this iFi page also: https://c4w4s3k2.stackpathcdn.com/wp-content/uploads/2019/01/iFi-audio-Tech-Note-Why-does-my-system-hum.pdf   And to answer your question, yes, I would tend to agree - that is what I think. But - I have not studied and decoded the iFi marketing speak, and I have not listened to those products in my system.

 

Do let us know the result of your further investigations.             Thanks,       Mark.

[Taz777]

Question for someone who owns the Pre Box S2D: will it do MQA through the coax input? I know it will do MQA hardware decoding via the USB (computer) input.

[left channel]

7 hours ago, Taz777 said:

Question for someone who owns the Pre Box S2D: will it do MQA through the coax input? I know it will do MQA hardware decoding via the USB (computer) input.

 

No it will not, sorry. John says that would have required increasing the size and price, so he decided to decode MQA only via USB. 

[Taz777]

52 minutes ago, left channel said:

 

No it will not, sorry. John says that would have required increasing the size and price, so he decided to decode MQA only via USB. 

 

Okay, thanks. I was toying with the idea of buying one to try out with my Bluesound Node 2i streamer which only has coax digital out.

[Miska]

6 minutes ago, Taz777 said:

Okay, thanks. I was toying with the idea of buying one to try out with my Bluesound Node 2i streamer which only has coax digital out.

 

But Node2 can do decoding instead?

 

S/PDIF on the S2D is not so great though, so better used through USB only.

 

[fgribas]

I'm sharing all my findings regarding power supply and softwares that I use with the S2D. Long post 

Power supply. I've tested: Included switching power supply, 5v powerbank, USB port from computer (additional port, not the USB data cable), iFi iPower 5v, grounded iFi iPower 5v, Chinese Linear Power Supply.

Based on my listening, the best ones are (in the following order): 1- grounded iFi 5v; 2- chinese LPSU; 3- ungrounded iFi 5v.

I already had an iFi iPower for the S2D and was happy with that (significantly better than the included PS or 5v powerbank). But I finally found a Chinese LPS that has a 5v USB output + 12v output and also a 115v/230v switch. I have a 12v mini PC that I will use as an audio endpoint for Roon/HQPlayer. So a single linear power supply with 12v + 5v is what I wanted. This is the one I found: https://www.aliexpress.com/item/DAC...-linear-thermal-power-supply/32923450663.html

I ordered one, and while it was on the way, I decided to try the JSGT (John Swenson's Ground Technique) on my iFi iPower. Bottomline is: all switching power supplies suffers from leakage current. Linear power supply blocks most of leakage current. iPower has a ultra low noise output across the audio bandwidth. But iPower is still a switching power supply and suffers from leakage current.

The technique is basically connect the negative pole of the power supply to the ground pin of the same power outlet (or power strip) where the power supply is connected.
More details here: https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/

I made my mod a little different (aesthetically better) than the original idea of using additional female connector + male connector. Mind that these 2 socket male plugs must be connected to the same power outlet (or power strip).

This grounding made a great improvement. The Chinese LPS arrived later and it sounds good, it's sturdy and well-built. However the grounded iPower still sounds better.

Software and configuration. I find DSD128 better than DSD256 or DSD512 on the S2D. I thought it strange and looked for explanations. I found out this: https://positive-feedback.com/audio-discourse/raising-the-sample-rate-of-dsd-is-there-a-sweet-spot/

It's an article from an engineer involved in the creation of SACD at Sony. The article is from 2015 and now we have DSD256 or DSD512 capable hardware, like our Pro-Ject S2D. But capable doesn't mean optimized. Rough analogy: it's like a video-game capable of running a 4K game, but at 15 fps. I think DSD256 (at least on the S2D) still introduces some kind of distortion or artifact, because it doesn't sound as natural as DSD128. But again, this is all based on my listening impressions. One fact is that DSD128 already solves the problem of audio bandwidth noise that DSD64 presents.

Source material: I mainly use Qobuz and Tidal, both on Roon. HiRes from Qobuz is great! MQA from Tidal is nice, as long as we decode only the 1st stage on Roon and then upsample on Roon or HQPlayer. Then I upsample to DSD128 on HQPlayer, using poly-sinc-short filter and DSD5v2 modulator. The filter is a matter of choice, but it seems that DSDv2 is the "correct" modulator for this DAC. I came to this conclusion only after having such a clean power supply. Roon upsampling instead of HQPlayer does a good job. HQPlayer upsamples better, but Roon using DSD128 "Precise, Linear Phase" filter and "5TH order (CLANS)" modulator comes close. I also use parametric EQ on Roon, and it squeezes the best out of my Shure SE846 IEMs.

And the final piece after upsampling is JPlay Classic (only the driver, not JPLAY femto). I use Ultrastream engine, 500 Hz DAC Link and Kernel Streaming. 1000Hz DAC Link sounds even better, but it needs a dedicated audio computer so it doesn't have dropouts, but currently I'm using my work PC to everything. I also use Fidelizer software. I bought Audiophile Optimizer but still haven't tested because it also needs a dedicated audio computer. Using my mini PC for that is the next step.

And finally on the Pro-Ject Control Panel, the lowest available ASIO Buffer Size, and Safe Mode unchecked.

[Taz777]

2 hours ago, Miska said:

 

But Node2 can do decoding instead?

 

S/PDIF on the S2D is not so great though, so better used through USB only.

 

 

Yes it can but I don't like the analogue audio it produces. I did try again to listen to it a few days ago but connected my Topping D50 back in, as there's a significant improvement in the audio. Hence, I'm currently using the coax digital out on the Node 2i as the input to the D50.

 

The S2D would work with my desktop system via USB with no issues, but I really wanted to try it with my bedside headphones system that uses the Node 2i as a Tidal transport due to the higher quality sound (mainly due to the Amiron Home headphones.

[Miska]

12 minutes ago, Taz777 said:

Yes it can but I don't like the analogue audio it produces. I did try again to listen to it a few days ago but connected my Topping D50 back in, as there's a significant improvement in the audio. Hence, I'm currently using the coax digital out on the Node 2i as the input to the D50.

 

Doesn't it output the decoded data also through S/PDIF? Or does the S/PDIF go muted when playing MQA?

[Taz777]

1 minute ago, Miska said:

 

Doesn't it output the decoded data also through S/PDIF? Or does the S/PDIF go muted when playing MQA?

My D50 external DAC shows 96kHz when I play an MQA track via the Node 2i - suggesting that the Tidal app within the Node 2i is doing the first unfold (as is normal) and sending the resulting bitstream to to my D50 via the coax output.

 

There is a setting for the Node 2i to specify an external MQA DAC. I would imagine if I set that then the Node 2i shouldn't decode anything and send everything out of its output ports (USB, coax and optical). I'd love to try this out but the price point of the S2D is a bit above my 'disposable' budget where I'd be happy to take a hit if it doesn't work out.

[Miska]

2 hours ago, Taz777 said:

My D50 external DAC shows 96kHz when I play an MQA track via the Node 2i - suggesting that the Tidal app within the Node 2i is doing the first unfold (as is normal) and sending the resulting bitstream to to my D50 via the coax output.

 

OK, then it does all that is needed. There's nothing more to unfold...

 

2 hours ago, Taz777 said:

There is a setting for the Node 2i to specify an external MQA DAC. I would imagine if I set that then the Node 2i shouldn't decode anything and send everything out of its output ports (USB, coax and optical). I'd love to try this out but the price point of the S2D is a bit above my 'disposable' budget where I'd be happy to take a hit if it doesn't work out.

 

I don't think you win anything by doing this. Just let it decode all there is to decode and let DAC do oversampling using better digital filters than MQA's ones (what they call "rendering").

 

[Mark Dirac]

I have used my S2D exclusively to stream Tidal & Qobuz so far. Streaming hi-res and MQA all work fine. But today I tried playing some hi-res files through Foobar.

 

But S2D's display shows 44.1kHz.

 

Foobar shows the files correctly as 96kHz or 192kHz as appropriate. I have selected the S2D in Foobar's "output" tab in "Preferences". There don't seem to be any effects selected. The equaliser is not enabled. Windows 10 with the Windows App version of Foobar2000.

 

Why on earth would such a simple task not work?

[left channel]

4 hours ago, Mark Dirac said:

I have used my S2D exclusively to stream Tidal & Qobuz so far. Streaming hi-res and MQA all work fine. But today I tried playing some hi-res files through Foobar.

 

But S2D's display shows 44.1kHz.

 

Foobar shows the files correctly as 96kHz or 192kHz as appropriate. I have selected the S2D in Foobar's "output" tab in "Preferences". There don't seem to be any effects selected. The equaliser is not enabled. Windows 10 with the Windows App version of Foobar2000.

 

Why on earth would such a simple task not work?

 

Have you installed foo_out_asio and then under Playback > Output > ASIO selected the Pro-Ject driver?  The Pro-Ject website used to offer a PDF with foobar setup instructions for DSD playback, and those were relevant to PCM playback as well, but it was quite out of date and I see that on the new website that document is gone. Those instructions are still included in the docs for other products like the DAC Box DS2 Ultra manual however.

[left channel]

The S2D has received a nice review in this month's Stereophile. Ken Micallef's write-up is positive, though a bit limited. It also did very well in John Atkinson's measurements, and has earned a Class A spot in Stereophile's Recommended Components.

[asdf1000]

11 minutes ago, left channel said:

It also did very well in John Atkinson's measurements

 

[mrvco]

Has anyone compared the S2D with the similarly priced DAC1 from March Audio?

[asdf1000]

Congrats to John Westlake.

 

And thanks to @Miska for telling us much of the same (and sharing measurements) some months ago.

 

Another snippet (the last one I'll share).

 

[left channel]

It's sad that the article doesn't mention John Westlake at all, but as Pro-Ject no longer longer has a relationship with him they probably very studiously avoided any such discussion, focusing instead on their company founder and history, and on the product.

[asdf1000]

2 hours ago, left channel said:

It's sad that the article doesn't mention John Westlake at all, but as Pro-Ject no longer longer has a relationship with him they probably very studiously avoided any such discussion, focusing instead on their company founder and history, and on the product.

 

Do you remember John saying he was working on a version of the S2 DAC with network input?

 

Everything else much the same plus an OEM RPi board (not the usual RPi3 board we can buy)

 

Did that happen or fizzle or still happening, somewhere outside of ProJect?

[left channel]

50 minutes ago, Em2016 said:

 

Do you remember John saying he was working on a version of the S2 DAC with network input?

 

Everything else much the same plus an OEM RPi board (not the usual RPi3 board we can buy)

  

Did that happen or fizzle or still happening, somewhere outside of ProJect?

 

His independent MDAC2 project is alive and well, with tons of discussion on pinkfishmedia. For Pro-Ject I think he was involved with more of the S2 line, including the Stream Box and Accu Box/Power Box products, but all that is over and done.

[asdf1000]

2 minutes ago, left channel said:

His independent MDAC2 project is alive and well, with tons of discussion on pinkfishmedia.

 

I will head there for all nitty gritty details... but can you give a short summary of what this is? Key features?

 

Is that essentially a Pro-Ject S2 DAC with network input? Or something different?
 

[left channel]

2 minutes ago, Em2016 said:

 

I will head there for all nitty gritty details... but can you give a short summary of what this is? Key features?

 

Is that essentially a Pro-Ject S2 DAC with network input? Or something different?
 

 

It's much more of a DIY thing for everyone involved. There's been a lot of interest and much activity over there. I can no longer remember the details though, sorry.

[TomETS]

I'm installing an S2 on a Windows 10 notebook running Tidal desktop.  I can seem to get MQA to light up.  Any hints?

 

Thanks.

 

[creativepart]

You must use the USB connection to get MQA. Are you using something else like S/PDIF RCA or Toslink Optical connections?

 

And you have to have Masters box checked in the Tidal account settings (and of course pay for "hifi" services).

[Miska]

6 minutes ago, creativepart said:

You must use the USB connection to get MQA. Are you using something else like S/PDIF RCA or Toslink Optical connections?

 

You can always let the player decode MQA for you. That way you get a better result by configuring S2D properly and letting prior stages do MQA decoding.

 

[TomETS]

Windows 10

 

Tidal Hifi Subscription: Yes, Active: Yes

USB: Yes

16/44.1: Transmitted, no MQA light

24/192:Transmitted, no MQA light

32/384: Transmitted, no MQA lght

Tidal Desktop: Yes

Windows volume: Full

MQA/Master song selected: Yes

Latest firmware: 2.12

 

"You can always let the player decode MQA for you. That way you get a better result by configuring S2D properly and letting prior stages do MQA decoding." 

-Have not seen any setting for this option in Windows.

 

No luck o far.