DirectStream DSD128 support not available from Roon


#1

Please help me if I’m misunderstanding something. The DSJ supports DSD128 on all inputs - per the specs on the website DSJ pages. Under specs, it says specifically:

Data rate (DSD) Standard (2.8MHz) or Double (5.6MHz) DoP on all inputs as well as raw DSD on I²S inputs
But when playing back in Roon, over the network using Bridge II as the input for DSJ, DSD128 gets down sampled to DSD64. Here's a pic.

Roon signal path

I took this up on the Roon forum. It seemed curious because I’ve got all DSD manipulation turned off. All bit rate conversion turned off. Yet this happens.

I was informed that this is happening because, using Roon’s RAAT protocol, that the DSJ is informing the Roon core that it only supports DSD64. But that’s in direct contradiction to the published specs (over DoP).

What gives?

Or am I missing something? Thanks.


#2

The Bridge is in fact limited to DSD64 and has always been. When Bridge II was being developed, some of us asked for double-rate DSD support. Paul explained that it was not possible.


#3

OK. That sounds like a disappointing statement of fact.

In that case, what am I not understanding about the language in the DSJ specs page I quoted in the OP? Sounds like DSD128 on all input to me. To say that Bridge II is not an input would be splitting some real small hairs that would only be understood by someone familiar with the product.

When I bought it, I saw “all inputs”. The RJ-45 jack in back is a network input. Seems misleading.


#4

Apologies @magister. I neglected to thank you for your help. Thanks.

I had typed it in earlier, but erased it to put it lower in the post, once realized it was going to be more than a line or two, and forgot to put it back. Sorry.

And thanks. :slight_smile:


#5
scolley said To say that Bridge II is not an input would be splitting some real small hairs that would only be understood by someone familiar with the product.
In the DS Senior, the Bridge is an optional, extra-cost, add-on. It may be that someone familiar with the Senior wrote the specs for Junior without really considering the fact that the Bridge is built in to the Junior. I completely agree that this information should be clarified since it is misleading from a common-sense perspective.

#6

Thanks. That’s actually an importation point IMO.

I’d bet dollars to doughnuts that in coming up with the DSJ webpage, a lot was just copied from the DS page - data formats and inputs included.

And I can see where someone very close to the product would look at what I quoted, and think “But that’s not the Bridge II, those specs are different.”

But to an outsider - like me, making a purchase decision - all that would go right over my head. And it did. So learning this now is disappointing. I’m just happy to see there is a reasonable way that it could have been an inadvertent oversight.

Though now it’s understood, and IMO should be addressed.


#7

I see how this could happen and apologize. I added a note to the specs on the all inputs section that it does not apply to the Bridge II.

This happened because we’re nerd engineers. The Bridge II is not technically an input - and so the statement that all inputs handle double rate DSD is technically accurate.

From the other side of the coin, the Bridge is just another input - and I now get that. My bad.

Thanks for bringing it to my attention.


#8

Paul - Thanks. I would not worry about it too much. Putting on my “playing like I work for PS Audio” goggles, I can now see how it could have happened. But wearing my “I don’t know squat about PS Audio products, but am interested in a DSJ” goggles, it is misleading.

Honest mistake. Thanks for your attention to the issue. wink


#9

Does this DSD64 limitation also apply to Roon through USB?

Nice timing on this post - thank-you! I would have purchased one this morning if Sales had got back to me with a question I had. Now I need to think about it.


#10

The limitation is for the bridge only not USB.


#11

As a practical matter I would think Toslink would also not support DSD128 (and not always DSD64). Perhaps that should be noted as well.