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OAudio

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Everything posted by OAudio

  1. Indeed, Its 3000 odd pages long but there are a few gems in there. It was bedtime reading for me for some time when I was working out what platform to move to after developing the X99 server. Sign of an obsessed audiophiles I think 😀
  2. Hi, My first post in this epic thread so hello to all ! @StreamFidelity hi, perhaps I would not go as far as saying this is "solved". It is an excellent starting point, the C620 architecture is the best I have come across so far and in large part I think because of its clock subsystem design. This comment applies to Intel systems, I haven't used or looked deeply at AMD. The C620 is still a starting point for me however. A few posts further down in the "Building a DIY Music Server with custom made parts" thread I also say. "I used to use e
  3. Its not nice at all when a board dies without an obvious reason. I am not sure if clock replacement is a regular modification so apologies in advance if the following are things you know / have tried. CPR for the buffalo, just make sure you have a mask on they can be gooey around the mouth First voltages. Were you able to check the peak to peak or RMS voltage from the output of the Xtal that was originally on the board ? These days 0.8 - 1.2v peak to peak clock voltages are not uncommon as VCore voltages get lower with internal processor frequency getting higher. If the
  4. Black would work better for heat emission from the CPU cooling block, but the extra heat emitted would be inside the case rather than being transferred out of the case via the heat pipes / case's external heat sinks. I don't think the difference between black v's silver finish should be too great so aesthetics will probably be the decider . Black would look cool though.....
  5. Hi, Details are finalised and the my engineers have a production slot scheduled to cut the coolers and other parts (below) from billet in two weeks time. I still have not decided on colour of the finish either black or clear anodized. I plan to visit the factory to see some finish samples and look at the units in production so will confirm colour then. The rendering (in the above post) shows the cpu "riser" and its clamp for the securing heat pipes. In addition I am having four half clamps produced per riser. The half clamps are used in pairs clamp three heat pipes and
  6. Hi All, This is a rendering of one of the parts I'm making for packaging of my audio server development. There are a few final details to iron out with my engineerings but they will start cutting them from billet in the next couple of weeks with luck (waiting to get a production slot agreed). The cooler is designed to handle up to 200 watts of dissipation from an LGA3647. This is far higher than is required even for heavily loaded CPU. At 200w you would need a < 0.2C/w rated heat-sink which is a very large passive sink, but this is not really necessary for an audio
  7. @Nenon A few thoughts, its possible you may be looking at something a little different then you are expecting. Caps. The M-Lytics will be 47k uf. The server is described elsewhere as having approximately 0.7f in total. Maths says approx 47k uf per cap give or take. They can be difficult caps to apply in such large size for servers, personally I have found they slow musical response and its difficult to keep life and air in the music using them. Credit and respect to Taiko if they have found a way to apply them without these issues. Looking at th
  8. Hi Alex, Thank you for the warm welcome . I know you are already on your second iteration of a solution for USB transmission with the ISORegen, I love the concept. I read the white papers when they were published and thought they were brilliant at the time. They are a great compendium and analysis of influences on USB sound. It's refreshing to see such valuable information coming out in papers. I'v heard the ISORegen once, unfortunately at a show in a system components I had not heard before. It was very good but I'm looking forwards an opportunity fo
  9. Thanks its a very interesting read, Timing, Signal integrity (inc transmission, detection and cable effects), PSU influence, Onward processing, and USB transfer & error handling, all hotly debated :-). I think the excellent white papers @Superdadlinked above pull these into a broad and cohesive picture. OAudio
  10. Mocenigo hi, Bit error of 10^12 would do the job for sure...."if" you can get to this performance in a real life implementation. Personally I think there is a lot that needs to be taken care of in PC to DAC system set-up approach this. As I mention above the USB transmission eye detection margin is quite small for the receiver (DAC) at ~ 0.4v. Differential noise between the power supplies of the USB link's transmitter (eg the PC, packed with noisy buck convectors, high transient loads and even an SMPS if your unlucky) and the receiver (the DAC probably on a low noise li
  11. We are on the same page :-) The board is set up to be able to be switched between these options and to examine some ideas to manage transmitter / reciver differential supply noise. I have used this approch in other projects but lots and lots of unknowns with USB transmission so practical testing seems the best way to go.
  12. Hi Sandyk, Thanks for the thoughts. My rendering software can't show the second daughter pcb. The second board has a 4uv low noise regulator and option are built in for where it is powered from. I can use this / the PC supply in different combinations for transmitter and receiver bus power. Transformer ground current is a tricky one, its influance is going to show up twice if Im not mistaken from the PC supply and the DAC. Theres quite some thought behind the approach in both these areas but perhaps best to get the board built and tested then
  13. Beerandmusic, this is a very interesting thread. I am relatively new to the forum so its just caught my eye. It's very interesting that asynchronous transfer errors are not resent meaning that it is possible that data can arrive at the DAC uncorrected. I also think that the vanishingly low errors rates that are quoted earlier in the thread may not truly reflect how a real music system's USB interface performs. The low error referenced by the USB standard assumes that transmission conditions meet the USB standards signal eye specifications all of the time. But, consider
  14. Some good points being made here. Personally I ended up spending months and months on the characterisation of motherboards power behavior to be sure of capturing complete requirements (mentioned a little of this is the earlier post). As well as longer duration trace recording its important look extensively, in both time and frequency domains, at real time behaviours. Understanding dynamic behavior and relating it back to what is driving it in the PC is very important. Some systems for instance will throw out a mSec transient current spike as POST completes and processors are initi
  15. Martin hi, I used early Plextor M.2 SSDs for a while. They could be bought with the M.2 memory stick mounted to a full height PCIe card. The riser card looked easy to modify. This is just a random PCIe SSD card selection (I haven't researched it) but if I were trying to do I might research a card like this to see if the go faster shroud can be removed. Applying power means cutting traces from the PCIe board and wiring in your own, I am sure if this is something you would be comfortable with. https://www.goplextor.com/Product/Detail/M9P(Y)_Plus#/Spec
  16. My c621 server has one SSD, it's an Intel 128GB so nothing exotic. The purpose is only to hold the OS and playback software. No music is stored in the server. The disk can be turned of or physically removed from the machine after it has been booted from a RAM image. This allows for some good insights on the impact of the disk on SQ. Sound quality best first. Disk removed from system booted from RAM Disk in system booted from RAM Disk in system booted of disk Top line is very special SQ, but my c621 sounds so "real" that I don't get
  17. Guys, Great conversation, @Dev I am not familiar with the Euphony software package, that's a really interesting point about root access to UNIX and how that plays into a decision about processor count. @Nenon So seperation and optimisation of OS / audio software / device driver across physical CPUs (and RAM) is the targeted benifit. Thinking broadly, a model of how to configure resource optimisations will emerge, sort of "good practice", and details of this could vary for different OS types / playback software / device dri
  18. Austinpop hi I have read a lot of you posts in the past, its nice to say hello. There is no agenda here just a few relevant questions to the tread that people may want to discuss and we all may learn from the discussion. The thread has been growing quickly so you may not have seen a few of my posts (couple of links for convenience below). I know a reasonable amount about the c621 platform, and I hope these posts added to collective knowledge here. I try where can understand how hardware might be helping music reproduction, I don't know much about dual CPU sy
  19. All, I was taking a moment to step back though earlier to think about the 2 CPU direction. It is quite complex and expensive in relative terms to a single CPU c621 build. I was trying to fathom why go that route ? Is it following the established Sage build taken by Taiko with the Extreme server so likely to assure a good SQ outcome, this could be a reason in and of itself. Are there any known "USPs" or theories that people are driving to realise with the Sage dual 2 CPU route ? A few things circulating in my mind comparing with a single processor c621 build.
  20. Its spread across multiple sources and I tend not to compile as I read, but its out there if you look at c621 architecture information sources and board reviews. The summary above covers the key points regards the clock subsystem. OAudio
  21. Ver interesting, I have had my head down working on the c621 and had missed the 422 I will pull the documents and take a look. I think I understand our different level of emphasis on PCIe now with your network and graphics setup. I have gone down the route of all interfaces on-chip on the PCH, so network, USB, and storage. I think this gives CPU > DMI > PCH > direct on chip to USB / and SATA / and Network (the network uses another serial standard from PCI chip to a media controller on the motherboard, I forget what its called, but I think its still
  22. Jabbr hi, I didn't claim any experience running the EC modulators I don't know them (I think I mentioned them as DSPs in my post) so defiantly take your views on that. I am a relatively new user of this forum so its understandable to assume that I may by putting forward baseless ideas or opinion about the 621 architecture for instance. I want to reassure you that the comments are not purely speculation and are in fact based on many, many years of research both practical and paper based into a number of Intel Architectures. For sure I would say I am not your typical serv
  23. @Jabbr, @Peter Avgeris It's the combined architecture of the Scalable CPUs and c621 PCH together that really matters. Intel have really delivered a hand up with this platform. What I think are important (backed by much research and experimentation on most of the points) is; The clock subsystem. Wow this is where Intel have really helped out in the design. A single oscillator on the PCH generates the CPU, RAM, DMI, PCIe, SATA, USB and Network (for on-chip N/W) clock domains signals, All these domains and subsystems now locked to each via the s
  24. Good that we are on the same wavelength. To put some figures against this. A C621 LGA3647 (pretty much the worst case I have measured) easily pulls uSec transients of 7 amps from a LPSU that in turn feeds a DC ATX like an HDPLEX. This is a 140va transient going into the DC ATX. On the output of the DC ATX this is likely to be an 11amp transient on the 12v rail into the mother board. Actually probably more than 11 amps because the DC ATX has a few thousand uf of capacitance that shields the LPS from the true size of the transient. If an umbilical and chassis connectors
  25. Yes this is a good looking case I have been looking at it as well as an interim step to finalise packaging. Its worth thinking about the one or two box build decision a little more. IMHO a single case is the way to go for sound quality, no contest. I have gone down both routes and looked at the impact of umbilical's. A single box setups does take time to optimise component positions, particularly the magnetics and they are just well "big" which is not cool depending on what you looking for. But for sound quality I think they are the way to go. The HDPLEX case is a beau
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