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

[lmitche]

11 minutes ago, left channel said:

 

OK, I've finally done a full comparison of external power vs. USB power, with and without the USB REGEN.

Connecting the external power adapter makes the largest difference, with and without the USB REGEN inserted. The music sounds so much better, I am wondering if further improvement could be achieved by replacing the switching power supply with a linear power supply. No need for anything fancy, just a linear "wall-wart" like Schiit supplies with their products. Looking for anything prefabricated with that micro USB connector may be annoying though.

 

The USB REGEN adds further improvement, but not enough when external power is disconnected (which is surprising, as the USB REGEN replaces the USB power). This improvement comes only from the USB REGEN's reclocking, which is apparently better than the design in the Pro-Ject box, about which the Pro-Ject data sheet says "with our new proprietary clock design we have managed jitter rates of unrivalled 100 Femtoseconds, this easily outperforms many renowned and respected audiophile clock generators!"  I can't find specs on the USB REGEN other than it has a "low-jitter clock". There is more published about the ISO REGEN. Anyone? I know circuit design is more important than the bill of materials alone, but this would be interesting.

This is now comparing very well with my Magni/Modi 2U. For this test I played Louis Armstrong's Blueberry Hill in DSD256 with foobar2000, and listened with Beyerdynamic DT770 cans. Final configuration was: external 5v power adapter connected, UBS signal routed via a USB REGEN. The REGEN is externally powered but is not powering the DAC, because the DAC auto-switches to external power. After connecting the REGEN the Pro-Ject box looked like a new device to Windows, and I had to configure buffer settings in the Pro-Ject control panel for DSD256 again. Then all was well. Nice little box.

What kind of power supplies are you using with the REGEN and Project DAC? If they are SMPSes you should try John Swenson's ground shunt tweak with both boxes.

[lmitche]

For less then $15 it is highly likely you can greatly increase the SQ quality of your system by using the technique described here:

 

 

[lmitche]

Yep, 

7 minutes ago, left channel said:

Thanks @lmitche, that looks like a fun experiment. I'd just have to add a micro USB adapter to the end.

Yep, or just splice into your existing cable.

[lmitche]

17 minutes ago, left channel said:

Thanks @lmitche, that looks like a fun experiment. I'd just have to add a micro USB adapter to the end.

I look forward to hearing your description of the impact on SQ there.  John Swenson knows what he is doing.

[lmitche]

2 hours ago, Miska said:

 

It would be useful to have some objective data on this. There are also lot of DACs running from switched power supply, including the Pro-Ject Pre Box S2 Digital. Which, when running from my normal workstation, puts out better analog output performance than lot of high end analog gear.

 

The figures I've measured for it, running at DSD512:

SNR: 120 dB

THD: 0.00082%

IMD: 0.00009%

 

Source is my Xeon E5 workstation running Ubuntu Studio Linux.

Wow, great to see these numbers.  Thanks for sharing

[lmitche]

37 minutes ago, MagnusH said:

Makes no sense to spend $400 on a DAC and then thousands of dollars on improvement to USB and power.

Why not? That's what I have done here with my $550 ifi microIDSD. I started with Auralic Vega to Mytek Brooklyn to IFI microIDSD at dsd512 with lots of "guest DACs" in between, T+A, Bryston, Cambridge Audio, Marantz, Teac.

 

The sound quality I'm enjoying now is way above where I started and blows away my expectations of what is possible. The last thing I'd upgrade is the dac. It's the money spent on the upsampling machine, USB components and LPSUs that deliver the most bang for the buck.  The DAC is just one component in the whole system. It's the integration and matching of components that matters.

 

Nevertheless, given the low price point, and Miskas post just above, I am tempted to try the Project DAC once US distribution is in place. Maybe once again a less expensive DAC will yield an increase in sound quality.

 

There are so many ways to skin this cat!

[lmitche]

1 hour ago, MagnusH said:

A good HiFi setup is all about balance in my opinion, you want to select electronics and speakers so that diminishing returns are about equal on all components to get most sound quality for money.

 

For example, I am pretty sure that a Chord Hugo 2 without any extra will crush a iFi iDSD no matter how good power and clean signal you have. Of course, if you do use a Chord Hugo 2, then it makes sense to add an extra $1000 on something like a ultraRendu or Sotm sms-200 to get even better sound. For a DAC like Pro-Ject S2, a iFi iPower or a relative cheap USP tweak like iFi nano iUSB or UpTone Regen results in best sound quality for the money.

Isn't a chord Hugo 2 a $2400 DAC? Anyway, I wouldn't be so confident.  The little ifi microIDSD with Hqplayer upsampling to dsd512 is something special.

 

 But we will never know and it doesn't matter in the big scheme of things.

[lmitche]

30 minutes ago, Narbooty said:

 

So many ways to skin this cat is right. I'm trying to plan out the next few years of purchases(roughly, of course...a general road map at least) as my income will be increasing significantly in a year and a half. At that point spending the money on say...the Mytek Brooklyn...would be very doable. Perhaps breaking everything up into more individual components would actually give better returns in the long run and allow me to purchase some things in the meantime that won't need to simply be replaced/upgraded later(I know that once you get into this enough there is ALWAYS a potential upgrade, but I hope you understand what I mean).

So you have to realize that CA is a young field integrating high production scale, low cost commodity computing components with low production scale, high cost audio components. You will get further investing in commodity computer components and using a low cost DAC then tying your money up in an audiophile DAC.  The difference between DACs is going to be relatively low given that the same DAC chip is used at many price levels. On the computing side we are seeing new technologies like more powerful processors, faster storage options like Optane, USB 3.1 generation 2, USB isolation chips, next generation linear regulators . . . enabling higher rates of upsampling resolution and much lower noise levels.

 

If you can handle the diy aspects, investing in the computing side of the equation yields fantastic rewards, and sharing techniques and debating the results in the CA community is an enormous amount of fun, most of the time.

[lmitche]

20 minutes ago, left channel said:

Well. Back here at ground level, where my Pro-Ject box is simply a drop-in digital replacement for a low-cost high-quality Schiit stack, I have another suggestion for a linear power supply. This should perform better than my $11 Jameco/ReliaPro wall-wart, while avoiding the shortwave RFI plus line hum issues of the $50 iFi Power: the TeraDak U9VA Linear Low noise Power Supply, USD $44 plus s/h.

There are quite a few like that available from other makers in Asia. But I noticed the TeraDak because Darko used it in his test of the microRendu. Of course, he heard (or perceived) better sound when he replaced the TeraDak with a $3,500 LIO power supply customized with a few hundred dollars more in boards and cables. But, seriously? I suspect I'd have to upgrade everything else in my system — at 10x the price per component, plus several more 10x components — and build a dedicated listening room, before I'd be able to get any value out of anything like the LIO.

 

Similar proportionate cost multipliers accompany the usefulness of many other audio products priced in-between those two points. And moving in that direction would certainly lead, for one reason or another (plus another reason, custom-tailored for your spouse ) to replacing the feature-rich excellent-value DAC that is (or was, once upon a time) the topic of this thread.

Here is the famous "El Cheapo" lpsu used by many of us to power lps-1s.

 

https://www.ebay.com/itm/High-end-30W-DC9V-HiFi-Linear-power-supply-Regulated-PSU-for-DAC-headphone-amp/111706391166?hash=item1a0238427e:g:a8MAAOSwxYxUs6kH

 

Your Teradak choice is a good one as well.