Directstream DAC


#1

Streaming 2.8 mhz DSD file from Bryston BDP-2 to Directstream (via usb) yields a reading of “PCM 24/352”…help???


#2

DirectStream is to be trusted. If that’s what it reads that’s what you are getting. Now to figure out why. Perhaps there’s a setting in the Bryston? Perhaps someone here knows or you can contact Bryston. But I am quite certain DirectStream is giving you accurate information.


#3

Thanks much, Paul…never a doubt about the DS…or Bryston, however here is what they say:

“The BDP packs DSD data into a PCM carrier meaning that it doesn’t convert it to PCM but moves it like PCM. There are embedded flags that tell the receiving DAC that it’s actually PCM.” What can we surmise of this??

Also, some may recall, Elk (and others on the forum) have the same unit and have never mentioned this to my memory…


#4

Makes sense. The Bryston units package DSD as DoP over USB automatically, which the DS then happily plays. It is pretty cool.


#5

Thanks, Elk, but why does my unit display the file as a PCM at 24/352??


#6
jedi1 said Thanks, Elk, but why does my unit display the file as a PCM at 24/352??
If the DS displays 24/352 then it isn't receiving DoP. If it sounds good perhaps you are playing DXD (which is floating point PCM at 352.8k) or perhaps something (before the DAC) did a conversion to PCM.

If it sounds bad (or very quiet and noisy) then there’s a volume control or other processing corrupting the DoP so that the DS can’t tell that it’s supposed to be DoP instead of PCM.


#7

DSD over PCM fills all of a 24 bit frame with bits (8 bits are the DSD marker). For single rate DSD, I would expect the DS to display 176/24 as this is the equivalent data rate.

But the DS may set the underlying PCM sample rate to 352.8kHz when playing DoP.

[edit: I should have refreshed the page before submitting the reply. Thanks, Ted!]


#8

Your BDP is not recognizing the Direct Stream.

Go to your device settings page in the Manic Moose media player.

You will see audio devices.

PS Audio will probably be listed in red.

Check the box and touch apply.

The BDP will then transmit DSD to your Direct Stream.

But I believe that only single rate is supported at this time. pulling-hair_gif


#9

DSD is only transmitted via USB on the BDPs.

Unless there was an update to Manic Moose that I haven’t received yet.


#10
Elk said DSD over PCM fills all of a 24 bit frame with bits (8 bits are the DSD marker). For single rate DSD, I would expect the DS to display 176/24 as this is the equivalent data rate.

But the DS may set the underlying PCM sample rate to 352.8kHz when playing DoP.

[edit: I should have refreshed the page before submitting the reply. Thanks, Ted!]


The DS displays DSD64 or DSD128 for single and double rate DSD (I think the Bridge II beta may say DoP instead/as well, I don’t know…)

The DS doesn’t display an equivalent data rate, tho if you stop your DoP feed (or depending on your player software, pause it) you will see the PCM 24/176 or PCM 24/352 since the DoP flags stop. And nope, there’s no concept of an underlying PCM sample rate.

As other’s have said, if the source is single rate DSD and the DS displays 24/352 then something is upsampling and converting to PCM before the DAC.


#11
Ted Smith said And nope, there's no concept of an underlying PCM sample rate
Thanks, Ted. Excellent reminder.

I mentally default to PCM DAC mode, even though the DS does not.


#12
MrDerrick said Your BDP is not recognizing the Direct Stream.

Go to your device settings page in the Manic Moose media player.

You will see audio devices.

PS Audio will probably be listed in red.

Check the box and touch apply.

The BDP will then transmit DSD to your Direct Stream.

But I believe that only single rate is supported at this time. pulling-hair_gif


A thousand thanks to everyone (beginning with Mr. McGowan)…Man, what an extraordinary place to be in this world of audiophilia!!! I can’t express my feelings on how much all of you seem to care so much about helping someone you will never meet face-to-face to be at peace and joy with their DS (and PS equipment at large). Thank you is not ample gratitude.

MrDerrick, Sir, you win the prize!! I did what you instructed and, as they say VOILA’…or EUREKA!!! I am a very happy camper!!

I live not too far down the road from the Rosie’s Cantina that Willie sings about out here in the Hill Country of Texas and dinner and Tequila is on me if you are ever down this way.

John


#13

Woo Hoo! Thanks for letting us know and thanks Mr Derrick for the correct answer.4_gifsmiley-music005_gifmusic-078_gif


#14

Great!

Ted, Bridge II does display DoP as well as the DSD64/DSD128.