Question about sending DSD files to the DS DAC - USB vs Bridge II


#1

I plan to send my music files from my NAS to the DS DAC via roonserver (once Torreys is out). I expect this will work great for all my flac files. But I am concerned that it poses some problems with DSD files, which I expect to begin accumulating more of in the future. My understanding is the Bridge II can only accept DSD 64 (correct me if I’m wrong), but if I went with a Sonore microrendu through USB, I could send DSD 128 and higher. Will I be missing out on any significant difference in sound quality by sticking with Bridge and DSD 64? Is there enough difference to consider the microRendu and purchasing DSD 128 files? Any insight into these issues would be greatly appreciated.


#2

Bueller? Anyone have any thoughts or experiences on the sound quality difference between sending DSD 64 to the DS via bridge vs. sending DSD 128 or higher via USB? Is it a negligible or substantial difference?


#3

I wish I could give you an answer but I haven’t tried the Microrendu. Maybe someone else one the forums has.


#4

I’ve been thinking a lot about this but I don’t have a clear answer for you.

In my system SQ is noticeably better via the Bridge II than through a Windows 10 PC/USB. This is for all files including DSD64. The PC has Fidelizer Pro, a good quality USB cable, and is powered from a LPS; in other words it has some tweaks but more could perhaps be done.

When I compare the same recording in DSD64 vs DSD128 via USB, the double-rate file sounds better, at least for those few albums on which I done a careful comparison. The difference is clearly audible but not enormous; I can certainly live with the single-rate. Would the difference be more compelling with a better USB setup? That’s the question I can’t answer. I may invest in a µRendu to find out, assuming that it is a state-of-the-art USB implementation.

Meanwhile, I am buying most of my DSD albums from NativeDSD.com. If you buy a quad- or double-rate album, they let you download the lower resolutions for no extra charge. So I’m playing the single-rate versions and archiving the double-rate ones for future use.


#5

Thanks for the replies, guys. I think part of the issue is that the microRendu is so new there aren’t many of them in the wild. Like magister said, I may have to spring for one just to do this comparison for myself. I think I’ll wait for Torreys before making that commitment, though. I may very well be satisfied enough with Bridge II and DSD 64 that the point is moot.

Magister, I notice you are running the same preamp as me, except I have the LS2 version. Love the C.J. preamps and amps!


#6

Maybe there will be a Bridge 3 that does the higher DSD rates?? I love the convenience and sound quality of Bridge 2, and would prefer to stick with that protocol…???


#7

Please help me understand exactly what I’ve purchased in the PS Audio Bridge II. Specifically, I’m reading that it “decodes” only up to 192/32 and single-rate DSD, while the DS DAC itself seems to have a much broader list of input signals it can handle. When I use the Bridge II’s ethernet input is the Bridge doing the D/A conversion rather than the FPGA?

I don’t think I realized this when I initially shelled out the money for the Bridge II. Don’t get me wrong, the BII sounds great, but I’ve got this psychological adversity to downsampling my files, many of which are in higher resolutions that the BII can apparently handle.

I hope it’s okay that I jumped onto this thread to ask such a basic question.


#8

Don’t worry; all D/A conversion is done in the FPGA.

It’s true that B2 is limited to single-rate DSD. When it was under development, some of us here (including me) asked for double-rate to be added. Paul explained that doing so involved significant difficulties and really wasn’t possible; I can’t remember the technicalities at this point, but there were good reasons for not having it. I’m not sure why B2 doesn’t support higher PCM rates.

It’s a choice we make. I prefer playing from my NAS with MinimServer and not running a Windows machine for audio. Despite some tweaking, said Windows box still does not sound quite as good as B2, so that’s what I mainly use. On those rare occasions when I want to play a 2xDSD recording, I go with Foobar on Windows via USB. If you have more higher-res files and/or a better-sounding USB setup than I do, your choices may be different. But B2 sure does sound good, even though I wish it did 2xDSD.


#9

The DS does all of the digital to analog conversions. The Bridge II is just an interface that accepts UPnP data over your home network, converts it to I2S digital data (just like the other inputs do) and sends it to the FPGA. The FPGA can’t tell which input it is receiving data from. The 192/24 and DSD64 limitations I believe were said to be UPnP limits but I could be wrong (or, at least as likely, oversimplifying). I believe only the I2S inputs and USB can handle anything higher than 192/24.


#10

Bridge II can’t do double rate DSD because DSD has to be sent using DoP, which would package DSD128 to look like a 354.8/24 PCM file, which exceeds the 192 limit.


#11

Thanks guys for all the great information. 2xDSD is no big deal as I only have one title in that format. I’ll just have to set up RoonServer to deliver the right resolution when using the BII. I’m a little embarrassed, as I just looked at my music database and realized I have only 1 PCM album that is higher than 192/24! I guess I have nothing to worry about, especially now that I know that everything goes through the FPGA!

:redface:


#12

Nothing to be embarrassed about. We’re all learning here. That’s what the forum is for.


#13

Hi All,

I do get confused by the different possibilities for the different inputs on the DS DAC for DSD.
I would like to list what I think and hopefully someone can correct me if I am wrong.

Interface - Possibilities

DS DAC USB - DSD Standard (2.8MHz) or Double (5.6MHz) DoP

DS DAC I2S - DSD Standard (2.8MHz) or Double (5.6MHz) DoP and raw DSD Standard (2.8MHz) or Double (5.6MHz)

DS DAC BII - DSD Standard (2.8MHz) only DoP

Do I understand this correctly?

Thanks for any corrections or confirmations,

Chip


#14

The bridge takes DoP not raw DSD.

Single rate DSD via DoP works with all inputs which support 176.4k (including TOSLink if you are lucky, the TOSLink hardware isn’t speced for 176.4k but it works reliably at 176.4k in some systems.)


#15
Ted Smith said The bridge takes DoP not raw DSD.

Single rate DSD via DoP works with all inputs which support 176.4k (including TOSLink if you are lucky, the TOSLink hardware isn’t speced for 176.4k but it works reliably at 176.4k in some systems.)


Over the weekend, I was feeding DoP to the DirectStream’s coaxial digital input from a Squeezebox Touch (modded with the Enhanced Digital Output). It worked flawlessly for hours and sounded really good. No luck sending DoP via TOSLink from the SBT to the DS, however.

#16

Not that there’s any guarantee since the TOSLink receiver in the DS is only speced for 96k and the TOSLink transmitter in your source is probably only speced for 96k, but a better quality TOSLink cable might make the difference. I have a near the bottom end of the AudioQuest line plastic TOSLink cable and some glass TOSLink cables that work reliably in my system at 176.4k. I also have plenty of cheapo TOSLink cables that came with satellite receivers, DVD players, etc. that don’t work at anything higher than 96k.


#17

Thanks, Ted. The TOSLink cable I use from the Squeezebox Touch to the DS is the Van den Hul Optocoupler Mk II. Sounds awesome streaming TIDAL HiFi. No problem that I apparently cannot stream DoP from the SBT to the DS via TOSLink. It was just an experiment and I did not expect it to work (whereas DoP>SBT>DS worked great via coax and USB).