Thread: Super Nucleus

Absolutely great work, you did it! There are absolutely things inside it, I have to learn, especially the way you powered it and I hope once to build one myself.

Despite of that I see some improvements could be made

- I did some research about quality of SSD’s. Samsung is a good choice, I think server SSD’s or enterprise ssd can be better. But info about this and find what is most stable is a difficult thing to find a way through all the marketing talk.

- second the sata SSD. It is a normal one. Hardly no ones makes these, jcat is not willing to shorten it, but I found that Pachanko will make adjusted Sata cables at 20 cm long which will fit inside this nicely.

- Last: I would advise a more closed case and the heatpipes and heatsinks are missing . These things help cooling the whole pc and especially heatpipes from the processor are a welcome part. Streacom has very nice cases with heatpipes.

- I am fan of audiolinux. Nice to see you implemented it. Did you adjust the settings too in audiolinux? And the bios settings can also be adjusted.

Have fun with it, and enjoy the sound.

Originally Posted by Elberoth

Got tired of building another Nucleus clone and decided to build this Super Nucleus for a change - a server optimised for SQ for USB DACs.

It is based on Pink Faun USB card with OCXO (Oven Controlled Crystal Oscillator) and sounds just spectacular next to a regular Nucleus.

IMG_0137m.jpg

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The server is based on an ITX board with integrated 9-generation Intel J4125 4-core CPU, with max TDP of just 10W (dissapates very little heat when running Roon). I'm a firm beliver that low powered CPUs, which generate less EMI/RFI, sound just better. If you need more computing power to run some crazy DSD512 upsampling - you can use it as a Roon Bridge and offload Roon Core to a separate NUC i7. Same CPU is used by Ideon, 432 Evo and other server manufacturers.

The whole thing is powered by Ultra Low Noise 12V PSU made by LHY Audio. This is a great chineese company, a sub brand of Jay's Audio.
The USB card has a separate, 5V ultra low noise voltage regulator from Jcat, based on excellent LT3045 LDOs. Their noise levels are state of the art, but sometimes they may not be fast enough for digital circuits, so they are stiffened up by a pair of ultra capacitors. Ultracaps significantly improve the quality of your power supply by reducing both internal ESR and noise levels, while optimizing stability and maximum delivered current.

ESR of Maxwell ultra capacitors used is just 1.8mOhm and are 325F each. To better visualize how much is 325F - quality amps amps have 200.000uF capacitance in the PSU. Big monos may have 200.000uF per channel. That is 0.2F. And here we have two ultracaps 325F (!) each, with nominal current of 270A. If the starter in your car was running on 5V, you could easily crank your car with these (in fact, there are super capacitor based battery boosters on the market already, but they use 6 similar caps, to get the voltage up to 12V, as each ultracap is rated at 2.7V only).

The ultra capacitor board has a special circuit to limit the ultra caps inrush current (which could easily fry your voltage regulator if used without one) and disconnect the output when no power is present on the input (controlled by optical isolators to eliminate any possible leakage current).

Komp PF OCXO_m.jpg

This Super Nucleus runs Audio Linux with Roon Bridge, which I belive sounds a little bit better than the regular Roon ROCK OS, but can also run the later.

A friend of mine just tested it on his Gustard A26 DAC vis the LAN Roon Ready input, and the Gustard sounds much better via this server on USB - much less hifi-ish with more "musical/organic" sense, natural timbres and an easy flowing liquidity - than the Ethernet input.

That's a really nice build, Adam, well done. At some point if you're open to it, I may reach out regarding the specs on the BOM (Bill of Materials).

Originally Posted by Elberoth

At $3000, there are some design compromises, but having a MoBo with integrated CPU and heatsink, is not one of them. As I mentioned mi my original post - I'm a firm beliver that low powered CPUs, which generate less EMI/RFI, sound just better. If you need more computing power to run some crazy DSD512 upsampling - you can use it as a Roon Bridge and offload Roon Core to a separate NUC i7.

I have both Streacom Alpha F10 case and a desktop ITX MoBo with 12100T low TDP desktop CPU on hand. It doesn't sound as good as the integrated board with J4125. So not only it would make system $700 (or so) more expensive, but also would make it sound worse.

The CPU I'm using puts out so little heat, that Ideon for example decided to use a completley sealed case in their $19,900 Absolute Stream audio server:

Ideon-Absolute-Stream.jpg

(This is, by the way, the very best streamer I have heard to date, this side of Taiko Extreme and Pink Faun Ultra. Much better than top of the range 432 Evo, Antipodes Oladra and Lumin U1x.)

In my opinion this is a bit over the top solution, driven more by the manufacturer's desire for their components to look identical than anything else, but clearly shows how little heat this CPU puts out.

I do not have those kind of constraints, which is why I have chosen a very well ventilated case, with lots of openings on top, bottom and both sides of the case - more than enough to get rid of the heat generated by the USB card and CPU.

Very informative post, Adam, thanks. I like your sensibilities and insights about how to build these that are best-suited for a specific application. The key takeaways for me are 1) lower-power CPUs generally work (and sound) the best, and 2) don't over-engineer a solution for a specific set of functional requirements. When I used to teach DFSS to my my engineers in Biotech, they would tend to want to go "over the top"... because they're engineers. I'd provide the guidance, that it dosn't have to be engineered to a "Formula 1-level" specification, it has to be "fit for purpose". You don't need a "LeMans Hypercar" to get back and forth to work everyday, an Accord meets that requirement just as well.

I'd also stress what we called: "Design for X", where "X" are the "-iliites": Reliability, Duraility, Serviceability, Repairability, and Parts Availability." These aren't "sexy" functions and features, but they're key to the creation of real value and long-term customer satifisfaction. Cheers.

Originally Posted by Elberoth

At $3000, there are some design compromises, but having a MoBo with integrated CPU and heatsink, is not one of them. As I mentioned mi my original post - I'm a firm beliver that low powered CPUs, which generate less EMI/RFI, sound just better. If you need more computing power to run some crazy DSD512 upsampling - you can use it as a Roon Bridge and offload Roon Core to a separate NUC i7.

I have both Streacom Alpha F10 case and a desktop ITX MoBo with 12100T low TDP desktop CPU on hand. It doesn't sound as good as the integrated board with J4125. So not only it would make system $700 (or so) more expensive, but also would make it sound worse.

The CPU I'm using puts out so little heat, that Ideon for example decided to use a completley sealed case in their $19,900 Absolute Stream audio server:

Ideon-Absolute-Stream.jpg

(This is, by the way, the very best streamer I have heard to date, this side of Taiko Extreme and Pink Faun Ultra. Much better than top of the range 432 Evo, Antipodes Oladra and Lumin U1x.)

In my opinion this is a bit over the top solution, driven more by the manufacturer's desire for their components to look identical than anything else, but clearly shows how little heat this CPU puts out.

I do not have those kind of constraints, which is why I have chosen a very well ventilated case, with lots of openings on top, bottom and both sides of the case - more than enough to get rid of the heat generated by the USB card and CPU.

I agree that a lower EMI/RFI sounds better. However every single unit that uses power produces EMI/RFI. Limiting EMI/RFI is great, but what also need to be done is effective shielding with the case. And right shieling will be reached with aluminium, without holes. These openings pass through the EMI/RFI that it still produces which will result in interference with other parts in the audio setup.