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MDAC First Listen (part 00111010)

Discussion in 'audio' started by JohnW, Jun 9, 2018.

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  1. russel

    russel ./_dazed_and_confused


    To be honest the IP issue I don't care about but we will need some form of documentation even if it's just a circuit diagam and layout to give us a chance of getting it fixed if for any reason john is not able to.
     
  2. Ian M

    Ian M pfm Member

    I’ve always been concerned that John may the only person in the world who could repair anything but a simple fault. I don’t think I could trust anyone else to bring it back to the same state.
     
  3. JohnW

    JohnW pfm member

    It has always been stated that the sponsor helps to fund the development costs - that does not involve any ownership rights except the right to purchase the design "At Cost", nothing has changed in this regards and there has NEVER been any other suggestion. Nobody here is under any other impression - again your only trying to cause trouble, it would make no sense for me to spend so much time and personal funds on development for the funds amount raised via PFM development sponsorship.

    The funds received from the development sponsorship are a fraction of what has been invested into the project.

    I have ALWAYS stated that anyone unhappy with the final result will have the opportunity to pass there development funding onto a 3rd party (minus PayPal service fees) once the design is released to production. We will not open the order books to new orders (if ever) BEFORE all development payments have been satisfied (with either hardware or passed onto a 3rd party).

    If the final MDAC2 solution is now too expensive then I'm hopefully that the development sponsorship position (once the hardware is ready) will be easy to passed on to a new party as the "At Cost" is significantly cheaper then it would be offered at market price, making the 100 odd "At Cost" units a good deal :)

    The DevDAC with its Dual ES9038's and DSD / HiRes support and MQA is pretty much 100% inline with what was initially proposed - if there is strong feeling about the MDAC2 cost escalation then we can quickly spin board the DevDAC into an MDAC format PCB - however sonically and feature wise its FAR behind the current MDAC2 DDA platform.

    Please advise if you would seriously consider the DevDAC formatted into the MDAC PCB or wish to pass your "At Cost" position onto a 3rd party once the design hits production.
     
    Last edited: Feb 13, 2019
  4. russel

    russel ./_dazed_and_confused


    It's not a question of trying to "cause trouble" you have to accept some responsibility for the state of this project, are you seriously surprised that people who wanted a DAC upgrade are bitching about having to pay for a bespoke high definition LCD panel? Some explanations would be nice, why expensive transformers rather than an op-amp or discrete solution?, are they really better?if so why?.

    Edit. Given the problem variants and side projects have caused in this project I think it would be a folly encourage another variant, just finish this one and I will make a go/no go decision.
     
    Hawtin and HarryB like this.
  5. BigDog

    BigDog pfm Member

    So... Standalone DETOX supporters will not have advantage of the enhance decorrelation...unless they commit to a DAC?

    We have all at one time or another purchased an item only to have it superseded by the next "latest & greatest" version. In THIS case, we do not even have the standalone DETOX in hand and already its technology has been superseded by an internal version with the "best decorrelation performance" with "greater sonic performance".
    By how much does the standalone DETOX come up short in your estimation?

    Sorry, John. Just trying to justify my staying on board for a standalone DETOX after what has been for me a 3 1/2 year wait.
     
    HarryB likes this.
  6. Stunsworth

    Stunsworth pfm Member

    My understanding - and I'm happy to be corrected - is that the cost of the casing, and assembly, for the Detox made it uneconomical for the number of items being constructed.
     
  7. clivem2

    clivem2 pfm Member

    Am I correct in thinking the decorrelation functions are only useful to the new MDAC and FDAC users? Other DACs won't benefit from this aspect?
     
  8. JohnW

    JohnW pfm member

    The Detox is a standalone device that operates in the USB domain while the internal Detox Advanced decorrelation can also work in other domains within the DAC design - internal circuit domains that the external Detox does not have access too. Its not an issue of the Detox being a lessor design, but that the internal Detox can be more capable as its an integral part of the DAC hardware (we can expand the decorrelation to other circuit sections not just the USB interface).
     
    Last edited: Feb 13, 2019
  9. JohnW

    JohnW pfm member

    Clock-locking mode of the Detox is currently only compatible with MDAC/MDAC2/FDAC but there will be other Branded DAC's released in the future with the Clock-lock interface.

    The Decorrelation mode works with any USB DAC.
     
  10. JohnW

    JohnW pfm member

    The IP is contained in the Schematic diagram - so the MDAC2 / FDAC schematic will NEVER be publicly released - this will be part of the sales terms.

    WRT component level servicing, due to many factors which make this design not fit for Mass Production - the DAC will not be serviceable by third parties (apart from simple full PCB swaps).

    1. 80% of the IC's are leadless / BGA packages requiring advance rework / Xray inspection (I have invested in both BGA / XRAY PCB inspection / rework systems for MDAC2 / FDAC in house production)

    2. The clock circuits require a full phase-noise measurement system for calibration and optimization - these calibration coefficients are stored during production into local EEPROM, any change of components in these circuits requires re-calibration.

    3. The Detox Circuit block is based on Quantum breakdown effects of reversed biased silicon junctions - the level and spectrum is statistically analysed stored in local EEPROM so that the level can be nominalised and also "Accurately" indicated to the user.

    4. The Transformer / Passive stepped attenuation level errors are calibrated and compensated for during production via software - these error levels and common-mode errors are stored in local EEPROM

    5. The Turn-over point of the Clock oscillator "Oven" temperature controller is analysed and stored in Local EEPROM (as well as other operating coefficients).

    6. Other unique circuit blocks I'll not discuss here - again requiring VERY specialized equipment and custom calibration software.

    7. Many IC's used on the MDAC2 / FDAC PCB require production line programming / Firmware fuses set - these again require programming interfaces / adapters and NDA's from the manufacturers for the production configuration software.

    For the above reasons the design is not fit for Mass production (as I've stated before), for this reason its also NOT reparable without considerable specialized equipment and custom production software with related setup test-jigs and knowledge. If you want a conventional design that can be serviced by a competent engineer without specialised equipment - then the DEVDAC is such a suitable design.

    The only advantage of releasing the MDAC2 / FDAC schematics would be to allow 3rd partys to gain an insight into the unique IP I've clearly spent significant time and funds developing and this is NOT part of the deal here - never has been, never will be !!!

    I still service my designs for Pink triangle (1991) upto my latest Audiolab designs - it will be the same for MDAC2 / FDAC. When my time comes, then Jarek who works with me will surely take over the task :)

    The PCB's can be "Blind swapped" in the field as all the calibration / optimization coefficients are stored locally on each PCB - the system MCU then reads these coefficients from each uniquely calibrated PCB for operation.

    Once the design is released, the level of design sophistication will become self evident and put stop to any notion of external component level repairs!
     
    Ian M and uwe061 like this.
  11. JohnW

    JohnW pfm member

    More specifically that I have to order an MOQ of 200pcs chassis at an upfront cost of around GBP120 each + any importation Taxes / fees + shipping etc (this is the complete mechanical hardware including packaging).

    So I'm waiting upon significant spare funds so that I can personally pay for the whole shipment - only then can i be sure to know the actual cost of the chassis. Before I have actually imported the chassis I have no idea of the real cost and so cannot ask for the funds "At Cost"...

    As second factor was the decision to included Advanced Detox within the DAC - its really the best decision WRT audio performance... it would make external Detox redundant / not cost effective.
     
    Last edited: Feb 13, 2019
  12. simonom

    simonom pfm Member

    Thank you, John, for taking the time to explain where you are with the project. It's much appreciated.
     
    Rune, Hawtin, Bob L and 7 others like this.
  13. lapkwan

    lapkwan pfm Member

    the division between perfectionist dreamer and pragmatist with consumer rights in mind can never been mended
     
    paulski and HarryB like this.
  14. russel

    russel ./_dazed_and_confused


    Some of the practical considerations are the original MDAC was 500UKP so clearly that was the market slot people were in, also there is the not insignificant detail that there being about a hundred people in the project, tend to be late middle age on a statistical basis five or six will have died since this project started.
     
    lapkwan likes this.
  15. lapkwan

    lapkwan pfm Member

    I am a pragmatist, though I know very little about the technical details involved I definitely want John to put an end to his endless crave for perfection (any?) and have the product delivered asap.
     
    HarryB and russel like this.
  16. iansr

    iansr pfm Member

    There is so much nonsense in that post. Of course the IP belongs to John and he is entirely within his rights to protect it. As for what people wanted, I think you will find that most of the contributors are expecting a DAC that will compete with and maybe even better the best of what’s out there.
     
    jarip, JohnW and Rune like this.
  17. russel

    russel ./_dazed_and_confused


    It's not nonsense any more than your post is, it's a point of view and from my point of view it's correct YMODV. Also will your ears be good enough to tell it's the best DAC out there and will you be alive when it's delivered are just two things to consider.
     
    HarryB likes this.
  18. iansr

    iansr pfm Member

    I think you’ll find that Intellectual Property Law has somewhat more substance than someone’s point of view.
     
    JohnW and jarip like this.
  19. Rune

    Rune pfm Member

    Russel it sounds like you should say to John you want the DEVDAC upgrade for your MDAC.
     
  20. misterdog

    misterdog Not the canine kind

    £ 599.95 when released, I paid that in Feb 2012.
     
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