DirectStream Connection to Nucleaus+


I just purchased a DirectStream DAC with the NetworkBridge II. I’m wondering what will be the best way to connect it to my Roon Nucleus+ (powered by a SoTM sPS-1000). It supports USB or ethernet. They are located next to each other. Thanks in advance.


You can use the bridge II


@epiekarc - In short, I’m not a fan of USB cables; some are and that’s cool. They recommend a reclocker for Nucleus USB (nucleus does not re-clock) to DAC. If I was to do it again, I would do it the same way I did. Think about system evolution too. If I went w/ USB, I would have to sell the USB gear when I get the PF 2.16 because I want to go I2S into the PSA DS DAC and get rid of Bridge II down the road. I can use the AQVOX SE to re-clock and clean the Ethernet signal going to PF 2.16. I have 100ft of CAT7 from great room to music room. There should always be a present system block diagram and future BD. Every move you make should help that progression and each architecture change has to be thought out.

My Nucleus+ is connected to my PSA DS DAC, bridge II using AQVOX SE GBENET switch. My wireless router (another room) is connected to my AQVOX SE in the music room using CAT7 Ethernet cable w/ Talegartner connections. The AQVOX SE re-clocks and cleans up the incoming Ethernet signal to the Nucleus+ and DAC; using AQVOX CAT7 (0.5m) custom Ethernet cables from AQVOX SE and Nucleus+ and DAC. I also use Sbooster MKII linear power supply and Ultra MKII active filter for AQVOX SE. I use Sbooster MKII linear power supply for Nucleus+. I have both Sbooster MKII LPS hooked to PSA P20 using PSA AC10 power cable. If you set up the Nucleus+ properly (great Ethernet cabling and power), your reward is really amazing and reveling streaming. My Nucleus+ sounds almost as good as my PSA DS DMP. With convolution filtering, better in my music room. I thought PSA DS DMP would never be challenged with streaming. I am so glad I set the Nucleus+ properly. Good 2 channel is about selecting the right components; great 2 channel is about power, grounding, and interconnects after you have selected the right components. In short, lowering the noise floor. Ted and Paul discuss this in depth throughout the forum, videos… You have (2) choices: USB or Ethernet because the HDMI connector is just that HDMI. I chose the Ethernet approach because the AQVOX SE and CAT7 cables added a level of amazing I thought was not possible. I hope the block diagram helps with ideas. In the end, every system should please the owner. I can’t wait to start listening to my system when I get up and fall asleep a lot of nights listening with 15 hrs min listening during the day. If the choices you make cause this level of enthusiasm, then you have done your homework… :slight_smile:

In addition, I hope you bought a nice SSD like the Samsung 860 Pro for your library. I love it. I use my OPPO 103 to rip SACDs and store the dsf files in my Nucleus+. I assume you bought your Nucleus+ for convolution filtering or you have a massive library. That was a $1K decision going from Nucleus to Nucleus+; assume you required the I7 platform for library or a lot of DSP functions needed for the increased: processing power, RAM, and OS storage?

With the PSA DS DAC, don’t let the Nucleus+ authenticate the MQA and turn off your Sample Rate Conversion (DSP zone). Let the PSA DS DAC w/ bridge II perform the conversions and authentication. Ted has done an amazing job with snowmass build and the bridge II is pretty good.

I’ve been running this set up for about 6 weeks and it is amazing. In a few years I will move from Nucleus+ to Pink Faun 2.16 or their present (2021) flagship streamer. Getting the Nucleus+ showed me streaming can be better than optical and 100X less drama than LP. In short, streaming has entered the audiophile realm and moving upward. I need to first get the PSA BHK preamp (2019), then PSA BHK 300s (2020), then PF 2.16 (getting rid of bridge II for I2S; 2021), then PSA TSS (2022)… the evolution…

This should give you some food for thought on the choices I made/making and a few suggestions once you hook up the PSA DS DAC with the Nucleus+.

Present Block Diagram

Future Block Diagram

Future Rack


That my friend is a well thought out plan. I love the diagrams!


@knecht - Thanks! This forum is used to share ideas and help one another. I could have answered the mail and just said I don’t like USB and go Ethernet. Many members have helped me along the way and my intent is just to share ideas and discussion. My ideas are no better or worse, they are just ideas. They cost me time and thinking and sharing. No system is perfect; no system is the best… they are systems that please their owners. In the end it is all about listening and enjoyment. As an engineer, half the enjoyment I get is thinking about my next move. I build it on paper; then think about the why, is there a better way. Does the system fill the intent? Is there a cleaner, better approach. Does adding a new component add better sound? Why will it add better sound…?



Thanks so much for your post. I am several evolutions behind you but am looking to do something similar. I just recently got in to streaming via my DS Senior purchase and added Roon and Tidal. My Roon core and ripped library are running on an old 2008 MackBook connected to a netgear switch connected to the DS bridge II. I have an Oppo BDP 105 which allows me to rip SACDs so I have DS files in my library.

I am quickly outgrowing the MacBook and am considering the Roon Nucleus as I don’t think I can wait for PSA Octave. I too am also pretty happy with how things are working so far and now I just need to optimize things like lowering the noise floor. From good to great so to speak.

Glad to hear that you have had positive experiences with networking gear selection. Other than bandwidth what are the benefits of going with Cat7? I’m not too familiar with all the flavors of Ethernet cabling as I stopped tracking after cat5 :stuck_out_tongue_winking_eye:.

Lastly, fully appreciate and agree with your design first philosophy. If you have a proper design in mind up front each investment will be a building block to the sound you are trying to achieve.

Thanks, Alan


@ayang90 - The big discriminator in my Ethernet approach was CAT7 (very good cable and connectors) cabling and the AQVOX SE switch. That switch is not a Netgear switch. That switch is for audiophiles. I’ve attached a CAT5, 6, and7 spec differences for your digestion. Understand, going CAT7 is not about BW, it’s about EMI and crosstalk. I assume you have not thought about DSP, due to your choice of Nucleus instead of Nucleus+. In Roon, when you are looking at the processing path, you will see a multiplier. That indicates how your processer (I3, I5, or I7) is keeping up. Each time you add features (SRC, convolution filtering, auto leveling, head phone filtering…), the processor multiplier will decrease. When it falls under 1X you have arrived at the limit of performance. So, I get 78X on my path with everything added… tells me 1/78 of the processor is used. Now, 0.5X is 200%… see where this is going… I bought a Nucleus+ so I would never worry about all the added features I would require. That was $1K decision; however, I’m using convolution filtering; might buy an IDS-4 HP next year, on and on… Also, I have ~175GB library so I went the 1TB SSD (Samsung 860 Pro) so I will never need more library considering my streaming is almost as good as my PSA DS DMP. I have added linear power supplies so my music room never sees SMPS. I even bought a LPS for my wireless router. Very clean power helps all the components.

Also, it took me 30min to set up the Nucleus+ and AQVOX SE switch. That includes: cabling, power, backup file location, complete device & DSP settings, and network addresses on my MSI laptop to start the transfer of all my wav, dsf, and flach files. It took about 5hrs to transfer the library (MSI wireless connection to Nucleus+ SSD library). Understand, buying a music server is a lot about the software engineering; not just hardware engineering. The Roon Nucleus+ has had zero drama since day one. One reason is the incredible software engineering. The only thing I would have liked to see was an I2S and the reason was they stay in their swim lane. Great software company stays with what they are great at… SW. They leave the audiophile to the audiophiles. Pink Faun seems to be an exception and I’m sure that took years. The cool thing is that they are a few engineers that create amazing products. I can’t wait to see how they are going to raise the bar on the PF 2.16. Right now they are working on an in-house oscillator.

Hope this helps…


Why is there a USB port shown in the Bridge II literature and video?



The early bridge boards had a USB port, but it never was designed for playing off of. It was similar the SD card for the PWD or DS, or the USB of the Jr - Just for software updating.



Wow a lot to think about. Thanks for calling out the audiophile quality switch. Didn’t know such devices existed.

Your future roadmap also looks awesome. Good luck with getting there.



@tedsmith - yeah, never considered USB from the start… In the future I think Bridge III will come before I have PF 2.16 planned so that will be tough, thinking Bridge III or pulling trigger on PF 2.16. Yeah, when I saw the post, I looked at Bridge II pic and saw USB… weird… thanks for clearing that up for E’s decision; or, no decision necessary…:+1:


Thanks @cardi for the info. I’m actually trying to go the opposite direction, less is more. I have a smaller library, and wanted to make sure I never pushed the Roon to a point where it would create sound quality issues.

I’m a bit confused why clocking would be a topic in USB, since RAAT also throws timing out the window. That’s the point of the DirectStream DAC (single master clock between content and analog, right?). Currently I feed my Audio Research DAC7 over digital XLR, from my SoTM sMS-1000. I’ve been very happy with it, expect the LMS interface. I’ve had one issue to the next with the control systems (iPeng is poorly laid out and has too many bugs). I can’t even play Tidal from iPeng.

I’m still trying to understand if there are differences in the data delivery from the Roon Nucleus+ to the DirectStream DAC over direct USB or ethernet. Does one support more options or bandwidth?

All content I care about is stored on the Roon internal SSD (Samsung Pro 4TB, I only need about 500GB last check). Yes I’ll stream from Tidal or Qobuz if they ever come stateside. But the Roon will feed my Crestron system, for general listening. I bought the Network Bridge so that I could push audio sources from Crestron (Kaleidescape, BD, etc) to my listening room, so I’d have access to all content regardless of location.

I’m a big fan of simpler is better, especially when I’m in 2 channel listening. More items in a signal path typically adds unwanted noise or removes details. I’m definitely going to try bypassing my GSPre and feeding my GS150 directly with the DirectStreamDAC.

To that end, removing a switch from the equation seems potentially better. So again, anyone know if USB or ethernet offers different specs as far as bandwidth, noise, etc?


@ayang90 - yeah, got to have a plan. However, like Mike Tyson says… Everone got a plan till they get punched in the mouth…:smirk:


@epiekarc - your questions answered by Ted in two words… “no USB” on Bridge II.


I’m looking to feed the DirectStream DAC (input), not output from it. Look at the digital inputs, it’s there. Anyone that has more knowledge about these care to help out?


The Bridge input on the DS is the ethernet input, the bridge only supports up to 192k PCM or single rate DSD (DSD64).
The USB input on the DS accepts upto 352.8k PCM (24 or 32 bits) and single or double rate DSD (via DoP).

There aren’t specs on how much noise is passed by the various interfaces. Fundamentally the computer industry doesn’t care about noise until it interferes with the proper function of a device. So USB and Ethernet are not designed for sound quality.

Outside of supported sampling rates the real issue with various inputs is electrical noise and groundloops. (The DS rejects jitter better than most DACs so it’s not as much of an issue in this context.)

The Bridge has a theoretical advantage with electrical noise and groundloops since Ethernet is transformer coupled, but remember the hardest electrical noise to get rid of is the higher frequency noise which passes right thru the transformers (or else they would block the Ethernet signals.)

USB is perhaps the worst input for passing noise - it requires a ground and VBUS connections. VBUS is the 5V line that is there to power USB powered devices. But it’s also the signal line for letting the host know when a device comes or goes and if that device is a hub or not. In general lifting the VBUS line will cause unreliable behavior with various combinations of hardware and software (but not all such combinations.) Further since the high speed data signals are right next to the VBUS and ground signals that high frequency noise can add noise to the VBUS and ground signals.

Ground loops are a problem for any system even with a perfect DAC. Using balanced connections can help a lot. But no solution is perfect and our ears are sensitive to roughly 1 in 100,000 to 1 in 1 million so small imperfections can be quite audible at times.

All of this is sort of beside the point: all inputs to the DS can be made to sound good: the amount of effort for a given system isn’t very predictable without a lot of info about that system. The Bridge input often has a leg up in that for many systems it’s easier to get good sound. On the other hand it’s twitchier so for those that don’t want it for it’s user interface I’d recommend stating with any other input.

Personally I greatly dislike the DLNA type interfaces, they don’t really let me see my music collection the way I want to. And since USB has the bandwidth I need for some of my music I use it.

Many find the DLNA user interface much more appealing than I do and they don’t usually work great without a bridge or some other streaming hardware.