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

[Kilauea50]

3 hours ago, left channel said:

 

That is just part of the jack, not the part that's soldered to the board, so maybe you can force it back in temporarily. But it is defective and should be replaced. A full page in the latest Audio Advisor catalog is devoted to this product, so I assume they have ordered plenty of stock.

They just called. They have none in stock but they are going to "RMA" mine so maybe it will be fixed at the very least

[left channel]

1 hour ago, Kilauea50 said:

They just called. They have none in stock but they are going to "RMA" mine so maybe it will be fixed at the very least

 

I expect they'll just send you another when they have stock. FYI they offer a "30-day Money-Back Guarantee" on all or most items. See the bottom of this page:

 

[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.

[left channel]

37 minutes ago, Mark Dirac said:

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.

 

Meridian's own DACs glow "green to indicate MQA playback and blue to indicate MQA Studio playback". [Link]  And as we know pink/purple indicates detection of 1x software decoding.

 

"MQA studio" means the track was approved by the artist or producer, or verified by the copyright holder. I assume it's the copyright holders on the vast majority, because I've seen blue on remixes that I doubt the now-elderly or deceased artists and producers would have approved.

[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.)

[fgribas]

On 3/17/2018 at 11:51 AM, Mark Dirac said:

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?

 

 

I use a USB power-bank (1.0A) feeding S2D on its mini-USB 5v port. 

 

With that in place, I use a Samsung S8 directly connected to S2D USB. The result is very good indeed (for mobile source without upsampling). I also have been using the same setup with an iPod (and one Apple Lightning to USB 3 Camera Adapter) as my travel setup.

 

 

[trl]

@fgribas: Why do you want to use a power bank to power your DAC for? I found a couple of USB ports on my desktop computer with less than 1mV RMS of AC ripple & noise, which is quite acceptable.

 

I've attached 6 pics from 3 devices tested by myself recently:

- pics 1&2 from a CANYON +5V power bank: 20.2mV AC ripple & noise

- pics 3&4 from a DURACELL +5V power bank: 0.482mV AC ripple & noise

- pics 5&6 from a LENOVO 90W power adapter with USB hub included: 0.664mV AC ripple & noise

 

However, after looking at the FFT (2nd pic for each device) you'll realise that both power banks are SMPS (DC-DC boost boost converters) and the best FFT is from the LENOVO USB hub.

 

However, you could find a low-noise USB port in your computer if you dive deep into this...or you could purchase a +5V linear PSU from eBay. Also, DIYAUDIO forum has a couple of good users building cheap and very good +5V LPSU. One thing's for sure: stay away from power-banks, unless you have a scope around to measure how +5V signal looks like...or if the power bank is really designed for audio (7.2V battery with linear regulators inside!).

[fgribas]

@trl nice findings, thank you for sharing.

 

I'm aware that the voltage regulators inside these cheap power-banks are crap.

 

I bought 1 LPS for the DAC and 1 for the mini-PC (NAA). Both power supplies have not arrived yet. And so the mini-PC. It's painful to buy from overseas in my country...

 

So my main setup with the S2D is a laptop as source using Tidal over Roon. I don't have any measurement instrument, so all my tests are purely subjective.

 

So far I have tested this setup using 3 different power supplies: Included SMPS wall-wart, 1.0A port on power-bank, 2.1A port on power-bank. And the 1.0A port on the power-bank was the best. Without a power supply on the mini-USB port, my Windows won't recognize the DAC.

 

Every week I'm on a different city, and sometimes Internet/Tidal is not available. So my alternative setup is to use an iPod with offline Tidal content as source.

 

The laptop, being a noisy computer that has fans running on and is always connected to the AC thru a noisy SMPS, I always though it would be worse than the already bad power-bank.  So It didn't occur to me to test the USB ports on the laptop to feed power to S2D with this second setup. I just tested it. And hey, your right! Sounds much better! Thanks

 

Actually the 3 available USB ports results in different sound. But all of them are better than the power-bank.

 

So when I'm back to my main setup, I will test 1 laptop USB port for the S2D USB-B data + 1 laptop USB port for the S2D mini-USB power. The LPS should take 3-5 weeks more to arrive...

[asdf1000]

6 hours ago, trl said:

Why do you want to use a power bank to power your DAC for? I found a couple of USB ports on my desktop computer with less than 1mV RMS of AC ripple & noise, which is quite acceptable.

 

One thing to consider, which may (or not) apply.

 

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

 

But the S2 DAC won't block ground loops / leakage currents / mains power RF from a mains connected computer USB port supplying bus power, which a powerbank is immune from.

 

Pro's and con's with nearly everything in this hobby, or as they say, there's no such thing as a free lunch.

[sebassie]

As I said before, I use an old iFi USB between my Mac and the S2. No problems at all, no need for LPS or whatever power supply and 24/7 USB power even if the Mac is off:-)

[Miska]

1 hour ago, sebassie said:

As I said before, I use an old iFi USB between my Mac and the S2. No problems at all, no need for LPS or whatever power supply and 24/7 USB power even if the Mac is off:-)

 

For the sake of trying I tried that but it didn't work for me. I think the power input of S2 was pulling too much current from the iUSB's power output. Or something else. But S2 didn't properly boot up.

 

I just use it with the stock wallwart, because that works and performance is fine.

[Miska]

5 hours ago, Em2016 said:

But the S2 DAC won't block ground loops / leakage currents / mains power RF from a mains connected computer USB port supplying bus power, which a powerbank is immune from.

 

For ground loops, as long as you have the computer USB connected, it doesn't matter where you pull the power from...

 

But I USB cable with ferrite.

[asdf1000]

1 hour ago, Miska said:

 

For ground loops, as long as you have the computer USB connected, it doesn't matter where you pull the power from...

 

But I USB cable with ferrite.

 

If the S2 DAC is being used to drive headphones (as per the photo above) then if the DAC is powered by battery then there will be no 'loop', even if the computer USB source is mains connected.

 

I know I'm not telling you anything you don't already know. Just let me have this little win ! :-)

 

[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?

[Miska]

9 hours ago, Em2016 said:

If the S2 DAC is being used to drive headphones (as per the photo above) then if the DAC is powered by battery then there will be no 'loop', even if the computer USB source is mains connected.

 

I know I'm not telling you anything you don't already know. Just let me have this little win ! :-)

 

The wall-wart PSU is floating one, so it doesn't create ground loops... Ground loops would be mostly about connecting the DAC to some other audio equipment and to computer using USB.

 

[mfsoa]

I picked mine up from my dealer in New Jersey (Audio Video Synergy, Clinton) yesterday. Beat the snow!!

Had it on for a day now - Does all it's supposed to - 

 

DSD512 (Hqplayer), PCM 705/768 (sometimes have to set Jriver to half this rate, play for a second, then change back to 705/768 then it plays fine), MQA (hate MQA but Gaucho really does sound good), optical in from a cd player, spdif @ 176/192 from a Pi/Digione/picoreplayer/.

 

So far used in the main system direct to Digital Amp Co's Maraschino Monos but will eventually move to the computer to feed Audioengine A6s.

 

Sounds very good and could easily serve as one's digital hub/preamp in a fine system.

 

-Mike

[left channel]

Hans Beekhuyzen likes the S2D! This despite reviewing one of the units with the pink capacitors that should have been recalled, and discovering a bug in the Optimal Transient filter. He did not test MQA or DSD.

 

 

[mfsoa]

Hmmm haven't checked mine for the pink caps of doom. I'd imagine that the one I got, from the recent arrivals in the US, has been corrected.

 

I still get a pause a few seconds into each MQA track. Is this common or is there a fix?

 

left channel, I really want to thank you and others for your efforts in essentially beta testing this little guy!

 

- Mike

[left channel]

De nada, @mfsoa. It's been fun as well as frustrating. I have DACs that from day one just plug and play, but any DAC with MQA and other bleeding-edge features seems to have at least a few problems, and most of us have experienced at least some of those. Not always a pause a few seconds in, but some kind of pause or dropout within tracks, or a freeze in-between tracks, or something.

 

These problems may originate with Tidal and/or in the code MQA provides to manufacturers, but other manufacturers seem to have figured out fixes of some kind. I believe Pro-Ject is working on a firmware update that will solve this too.

[firedog]

1 hour ago, left channel said:

De nada, @mfsoa. It's been fun as well as frustrating. I have DACs that from day one just plug and play, but any DAC with MQA and other bleeding-edge features seems to have at least a few problems, and most of us have experienced at least some of those. Not always a pause a few seconds in, but some kind of pause or dropout within tracks, or a freeze in-between tracks, or something.

 

These problems may originate with Tidal and/or in the code MQA provides to manufacturers, but other manufacturers seem to have figured out fixes of some kind. I believe Pro-Ject is working on a firmware update that will solve this too.

In Darko's recent positive review of the S2D, he implies that the newest firmware pretty much solves all the problems. What still doesn't work the way it should?

And BTW, now that iFi DACs support MQA, there's some pretty stiff competition for this device. The iFi people (in response to my query) even stated that their DACs do know how to switch MQA filters on and off, even in a mixed playlist of MQA and non-MQA tracks.

[left channel]

1 hour ago, firedog said:

In Darko's recent positive review of the S2D, he implies that the newest firmware pretty much solves all the problems. What still doesn't work the way it should?

And BTW, now that iFi DACs support MQA, there's some pretty stiff competition for this device. The iFi people (in response to my query) even stated that their DACs do know how to switch MQA filters on and off, even in a mixed playlist of MQA and non-MQA tracks.

 

If the Optimal Transient filter is selected, after playing an MQA track (which disables the ESS filter per Meridian's requirements) then playing a PCM track, the filter does not properly reengage, and the music sounds "thin". This does not occur with other filters.  This DAC also seems to experience more MQA dropouts and pauses than others. There's also the laggy rotary encoder and other minor nits. Don't know if it's all fixable in firmware, but we can hope.

 

iFi's MQA upgrade turns their devices into "renderers", requiring software decoding doing the first "unfold" ahead of them in the chain. Also it disables DSD512 on the DACs that support it, dropping the top rate to 256. But they're quite intruiging nonetheless.

[nodoubt]

new here, but have been eyeballing the s2 for some time now.

just got one delivered yesterday, and so far , so good.

only a handful of hours on it , but it is going to be a very resolving dac to say the least.

ill report back when i get it loosened up a bit more.

awsome place here btw guys... glad i stumbled up on it looking on reviews on this s2 !

 

tc for now...

[left channel]

@nodoubt welcome! What firmware version is in your device? Press the "Menu" button, then press the down arrow button twice.

[nodoubt]

9 hours ago, left channel said:

@nodoubt welcome! What firmware version is in your device? Press the "Menu" button, then press the down arrow button twice.

thanks for the welcome  LC !

its the latest 2.12.....  that was the first thing i checked.

wish i had the nerve to open it up and see about those pink caps.

yall got me worried now !

i may do it in a few days after i get it broke in good.

i can tell you this..ive went thru the smsl m8, with ess chip...too bright

then the emotiva pt-100....nice build, features, but was lacking in depth

then cambridge dac magic plus....which i still have and am getting ready to send back..

it is a very musical box, nice and warm sounding, but is no where as resolving and transparent as this new s2 box.

i just got finished a-b testing both of these back to back, and when i went to the cambridge, it sounded like i threw a blanket over my speakers in comparison.....

actually hope this thing will mellow out a tad when good and broke in ?

any thoughts on that ?