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

[Mark Dirac]

25 minutes ago, trl said:

I'm looking further for someone testing it with a linear PSU as well.

 

For the sake of testing the improvement with a clean and decoupled PSU, would it be practical to power the DAC from 4 x NiMH cells, using something like this:

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

 

I reckon I would get about one hour of battery life - plenty for a bit of experimentation.

 

I guess this has been tried before, and there's a good reason why others are not trying it? Perhaps the source impedance of raw NiMHs is too high?  Add a capacitor in parallel (to reduce source impedance)?  Or perhaps that then causes problems with in-rush currents? (My Pre Box S2 Digital is still on order)

 

(I assume that 5V phone power banks must use some switching and therefore inject loads of noise.)

[Mark Dirac]

36 minutes ago, trl said:

 You really need a very stable power supply for the DAC.

Thanks trl. If what you want is stability, then you cannot get a more stable supply than batteries plus a low-inductance capacitor. Now - that may not be good enough (low impedance at all frequencies? In-rush current control? Something else?) - but it will be stable.

[Mark Dirac]

My S2 Digital has arrived.  But it's not working - there are driver problems and W10 settings reports "Driver is unavailable". Tidal plays at 44.1k irrespective of MQA pass-thu or not. I am confident I have the Tidal W10 program and the W10 "Playback devices" panel configured correctly. But I have no "Pro-Ject utility". And the firmware update utility from the web page refuses to run, with the missing .dll error. And there are no drivers on the website, only the firmware.

 

(Device was shipped with v2.12 and I am using a well-maintained Windows 10 PC).

 

I don't have a CD drive - do I need the CD? Is everything on the CD also on Pro-Ject's web site? Any ideas  please why the drivers have not installed from the box?

[Mark Dirac]

You're a hero, left channel. Thanks. Yes, amidst all the confusion and ambiguity, I failed to see the "enter S/N" box." Big oops.

 

So, is working now, although still some quirks:

• In W10 "Playback devices" control panel; and in Tidal settings, the DAC is called "2- Pre Box S2 Digital". I guess this is a result of me trying to install, delete, and re-install drivers. Most places else it is called "Pre Box S2 Digital", as expected. I am concerned that I have two different somethings installed.
• When playing Tidal without "Passthrough MQA" set, the DAC's display reads MQB" with a purple dot. (When I set pass through, "MQA" + blue dot shows, as expected.) What d'you reckon MQB refers to?

I note you have assisted dozens of customers, on several forums, over many months, and often with the same advice. So I have started a Google Doc to collate people's advice and discoveries. If you reckon this might become useful I can flesh if out over time and grant you edit access (pse PM me).

https://docs.google.com/document/d/12H0_F_gD2GY37XKHwrM3tQZRYcm84yzIrSy1MbmkFY8/edit?usp=sharing

[Mark Dirac]

Sure Aboulfad. I cannot figure out the Miska post you're referring to.

 

I bought in UK at the Bristol HiFi show from Audio-T imported by Henley Audio for £300. Lead time was 4 working days.

[Mark Dirac]

I have continued to flesh out the Google Doc attempting to pull together some of the key nuggets of advice for people wanting to understand more about this DAC.

 

https://docs.google.com/document/d/12H0_F_gD2GY37XKHwrM3tQZRYcm84yzIrSy1MbmkFY8/edit?usp=sharing

 

(Thanks for improvements and corrections by left channel.)

[Mark Dirac]

Hmm. Is my stock wall wart producing a surge when I power it off at the socket?

 

If I switch off the external PSU at the wall socket, the DAC resets itself. I imagined that this is design-intent. But - I noticed that when I switch off an external battery pack, the DAC does not reset. And if I simply pull out the wall wart's microUSB plug, the DAC does not reset. But if I switch off the external PSU at the wall socket, the DAC resets itself.

 

Does anyone's DAC reset itself when they switch off external PSU at the wall socket?

[Mark Dirac]

2 hours ago, dwaleke said:

No reset on mine when I unplug external power.    Using the iFi iPower since I had it laying around.

Thanks. How about when you unplug the stock wall wart - does it reset then?

 

(Your reply is ambiguous - I'm not sure if you're saying there is no reset with the iPower, or no reset with the stock wall wart. Or no reset with either?)

[Mark Dirac]

So we know what "MQA logo + blue dot" means.

And we possibly/sort of know what "MQB + purple dot" means.

 

But what does "MQA logo + green dot" mean?   Display also reads 96k. I am playing new masters recording at Tidal: "Ravensburg" by Mathias Eick on label ECM.

[Mark Dirac]

Thanks left channel.

 

left channel reported that he could get his S2D to work from Android if he inserted an Uptone Audio Regen. Has anyone discovered a cheaper way to inject power into the USB connection?  I imagine that a powered USB hub might work, except that (IIRC) it has been found that S2D will not work through a USB hub?

 

Has anyone tried a powered USB hub on Android?

 

[Mark Dirac]

New URL link to the Google Doc "Additional information about Pro-Ject Pre Box S2 Digital" summary document. (It tells us clicks and therefore how many are still finding the document of help.)

[Mark Dirac]

6 hours ago, Em2016 said:

The S2 DAC has nice low noise linear regulators inside, if the noise output / ripple of a powerbank is an issue.

This is borne out by several people who have reported little or no improvement by replacing the stock wall wart with a nice external PSU.

 

For the sake of trying to hear a difference with no ground loops / common-mode noise and no battery DC-DC switching, I bought one of these:

battery box with micro USB lead     $3

(It supplies a stable voltage 5.25V to 4.75V for over an hour with four NiMH AA cells - plenty of time to experiment.)

 

I can hear no difference (compared with the stock wall wart). But I suspect that this might be because the NiMHs have a significant internal impedance / ESR. I would like to stick a capacitor across the battery to reduce source impedance. Can anyone suggest a size and technology of cap to use please? I am nervous about plugging a charged capacitor into my DAC 'cos I know a charged capacitor can source high current transients and therefore voltage transients (a charged capacitor can often cause tiny sparks). Can anyone advise please on what size of capacitor would be "safe" to use to avoid the possibility of a voltage/current transient when plugging into the DAC?

[Mark Dirac]

22 minutes ago, buonassi said:

Would someone be so kind as to provide a summary of this kit please?  The idea of reading 34 pages just to get a few impressions puts the damper on my laziness streak.

Already done. Summary of PBS2D threads.  (Links to a Google Doc.) This lists all the reviews that we know of. They are all flattering.

 

What headphones do you have? Unless you have insensitive / high impedance headphones, there's nothing wrong with the headphone amp.

[Mark Dirac]

13 hours ago, Em2016 said:

10 hours ago, left channel said:

One DAC chip instead of two, among other differences. Basically it's called "S2+" but actually it's a minus.

 

Brief explanation of the differences between the three John Westlake Pro-Ject DACs is in the Google Doc thread summary. Also a list of all reviews which we know of.

[Mark Dirac]

On 20/04/2018 at 8:46 AM, Em2016 said:

 

I'll take further HQPlayer discussion over to your HQPlayer thread, since this is not exclusive to the S2 DAC.

Taken to here

[Mark Dirac]

My PC updated to Windows 1809 today and my S2D stopped working. It was a head-scratching waste of half an hour to get it going again.

 

When I first plugged in the S2D (into USB) Windows reported it was "setting up a new device" and that "is now working". But S2D did not appear in the sound options. The only place it appeared was in the settings page for Devices, where I was informed "driver not found". No plugging/unplugging and restarting would fix.

 

In device manager, I selected "update driver" and pointed device manager to search my hard drive and it found a driver & installed it. Now working.

 

I would be interested if anyone could tell me what's going on, why the 1809 upgrade would cause this one device's driver to go missing, even though Windows "set stuff up" when I first plugged the S2D in.

 

(I hate Microsoft.)   Thanks.

[Mark Dirac]

9 minutes ago, left channel said:

@Mark Dirac please let us know if this fixes the issue you reported above.

I'm afraid this is a day too late - as I said in my post above "I selected 'update driver' and pointed device manager to search my hard drive and it found a driver & installed it. Now working."

 

But I need to add a section about software versions to the summary document. I think there's 3 bits of software we use? (a) firmware (b) driver and (c) the "Pro-Ject  Audio Control Panel" which I've never understood. Is the XMOS software in the driver? Or is the XMOS software the driver? And who is Thesycon? Did Thesycon write the driver for XMOS? Hmm.

[Mark Dirac]

Has anyone noticed any improvements, or even differences, with the new (v. 4.47) driver?

[Mark Dirac]

I have given up with the complexities and ambiguities of MQA and Tidal Masters, and have moved to Qobuz. Thanks to left channel for the gentle persuasion.

 

But I am surprised to see such a baffling set of "audio output" options, and can find no explanation or FAQ answer.

 

My selected output "Pro-Ject Box ASIO Driver" does not appear anywhere in Windows 10, specifically nowhere in the Windows 10 Sound Settings. Is it the case that Qobuz is bypassing Windows's sound stuff straight to the Pro-Ject driver somehow, in a way which Tidal does not?

 

Can anyone enlighten me please? Left channel?

 

 

[Mark Dirac]

I recall someone saying that this annoyance is caused by Pro-Ject's driver for the IR HID stuff, that is, for Pro-Ject's W10 driver which handles the S2D receiving IR commands from its remote control and then sending those commands to the PC over USB. This person claimed that by disabling the driver (listed as "HID") in W10's device manager, that the annoyance is solved. (Although, of course, the remote control will then cease controlling the PC.)

[Mark Dirac]

I reckon that in the last few days we've been discussing three very distinct possible improvements to the S2D:

1. Noise injected via the power USB
2. Noise injected via the signal USB
3. Jitter in the (USB) signal

I believe that the S2D handles (2) and (3) particularly well, and it may be difficult to achieve improvements here. A large number of enthusiasts made £50 contributions to John Westlake to develop new techniques for controlling jitter, and John has proudly announced that many of the  developments were incorporated into the S2D.

 

From comments John has made over the years, I believe that his only concern with switching power supplies is not noise generated by the switching process, but common mode noise loops arising from the RFI suppression capacitors which are fitted to switching PSUs to control their EMI tendencies. Linear supplies do not need these capacitors. 

 

I have always suspected (no evidence) that this is why the manual confusingly talks about not using the supplied wall-wart when connected via (signal) USB - because if the S2D is connected to its PC/phone/streamer via USB, then there is more opportunity for common mode noise loops though the capacitors in the wall-wart, than there would be using optical or co-ax.

 

 

 

[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.

[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?

[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.

[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?".