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MDAC First Listen (part 00111010)

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

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  1. Asphaltradler

    Asphaltradler pfm Member

    @JohnW This price range is totally new to me. The Homepage states
    • PCB target cost £350 - £400 + Shipping
    And that was what we all funded 4-5 years ago. How could it happen that you changed the design to include 300 GBP of electronics PLUS 350 for transformers alone when the initial cost planned was 350-400 for the whole pcb?

    I think in each design there must be some limiting rules. And not the least of these should be: time range (it be producable in sensible time) and holding to planned price tag!

    If I had been willing to pay 1500-2000 eur for a DAC (BTW I don't get what all this GBP is about, since you are situated and pay your bills in the EU) I would have done so 5 years ago.

    We voted and funded for the best payable bicycle, not an interplanetary rocket. So the rocket science transformers for one seem to be quite out of place. And I don't remember those being mentioned in all the 3000+ pages of design talk up to a few days ago.

    Am I the only one who doesn't want to spend 4 years after the 450 Eur funding further 1100 Eur uncalled for (my rough estimate for the LOWEST number JohnW stated now, but certainly that number may still rise)? My self-built nCore power amp monos cost only 1050 eur altogether and I don't have the feeling that my system will reveal any differences between a 50 or 300 eur transformer or needs a super highest fidelity DAC. I thought then the idea was only to finance designing a better, best for money Mdac, which should be 'top of upper middle class' so to speak. I don't wanted to compete with 10.000 eur devices (which neither my ears nor the rest of my system are capable of).

    My few cents.
     
    lapkwan, JTC, mike9876 and 1 other person like this.
  2. Asphaltradler

    Asphaltradler pfm Member

    Not me, definitely. I would have prefered to spend time and money on enjoyable recordings instead of hours and hours of reading 1000s of posts about time and price creep. Never wanted to spend more than 750 P or so altogether.
     
    HarryB likes this.
  3. ti33er

    ti33er pfm Member

    I think John has said the original MDAC transformers will still work ...it would be optional for bespoke transformer upgrade component

    I too have nCore Amplifiers ...apparently a DAC like Johns is what we need to show them off; the only reason I still have my nc500 as I think it’s a very boring (neutral) piece of kit in my current config :)
     
  4. paulski

    paulski pfm Member

    We’re taking here about audio output transformers, the original MDAC doesn’t have any.
     
  5. JohnW

    JohnW pfm member

    The transformers refereed to are the custom designed Audio output transformers, these are not optional as the heart of the DAC design.

    The PSU transformers are a different matter and these are not costly items (if they would be required).
     
  6. JohnW

    JohnW pfm member

    Yes - Correct :) Custom Audio Output transformers.
     
  7. Rune

    Rune pfm Member

    And the output transformers means you do not need a preamp for your ncores.

    Agree MDAC2 is not what we signed up for, but I am very satisfied with what it have evolved into :cool:

    Maybe DEVDAC2 is closer to what was initially planned. Both performance and cost wise.
     
    jansen likes this.
  8. BigDog

    BigDog pfm Member

    John, any thoughts on my suggestion to offer the "enhanced" DETOX as a board which could be DIYed into a standalone unit?
    Thanks.
     
  9. russel

    russel ./_dazed_and_confused



    Why are the transformers so expensive?, Sowter who are normally twice the price of everyone else can do two DAC IV converter transformers for about 260UKP, also a 6 inch phone display on eBay can be had for about thirty quid, so why is it 110UKP for a display?.
     
  10. Vinz

    Vinz pfm Member

    30 quids? I would think that's a good price for a refurbished screen.
     
  11. russel

    russel ./_dazed_and_confused

    Go and check if you don't believe me.
     
  12. moosemeat

    moosemeat pfm Member

    The price will simply be a reflection of the bespoke nature of the product. iPhone displays, for instance, are pumped out in the millions, whereas the MDAC2 display will only be a couple of hundred or so... likewise, the custom designed Audio output transformers. The overhead for the iPhone display & the MDAC2 display will be pretty similar and must be recovered across the full output, which is why small production runs are much more costly.
     
    Rune, Bob L and JohnW like this.
  13. JohnW

    JohnW pfm member

    I'm not going to go into the fine details of the MDAC2 design - the design is proprietary and I've obviously spent a significant portion of my life over these past few years working on the design so I have no intention of revealing its more salient design IP.

    I find the tone of your questions rather offensive and I'm disappointed in you, the fact you ask these questions just highlights how little you understand.

    WRT to the transformer costs, these are Custom designs - and in fact the next (and hopefully last) design prototypes are the 5th or 6th design iteration - (maybe there have been more iterations - we started out working with Lundahl Transformers)...

    The design is very unique and NOT your standard I/V transformers (in fact other "I/V" transformers I'm aware off do not operate in Pure current mode). Due to the currents and impedance's involved in the MDAC2, these are LARGE transformers - soo large that we have had to machine the top off the plastic Bobbin to fit within the MDAC chassis. I've certainly have never seen any true "IV" transformer designs - only rather Amateurish applications of transformers in so called I/V mode - and its technically arguable that while they do transform impedance's they are not operating in true current mode - rather some Amateur DIY applications that have failed to understand the requirements of true I/V conversion (Virtual Ground - no "voltage" swing).

    WIth transformer Quality - size DOES matter and these are the largest transformers that can be squeezed into the MDAC2 Chassis.

    Again - I don't appreciate your "shit staring" WRT the LCD pricing, the panel I'm using costs over GBP225 including VAT (1 - 10 Pcs), sure 100pcs order will be cheaper maybe around GBP180 (with VAT), welcome to the cost of small scale European manufacturing... I sincerely doubt I'll be in a position to place an order for 100 panels in a single shipment - that's GBP 18,000 just for 100 LCD panels!!!

    Please go ahead and fit a 6inch phone display on the MDAC front panel - and while your at it, please also find the panel driver information (EE and software) for said panel with capacitive touch interface (must be parallel or LVDS interface (not MIPI).

    I need the Linux software drivers for the LCD panel and Touch interface.

    So when you have a High resolution IPS LCD panel that physically fits across the front of the MDAC front panel, has LVDS or Parallel interface, with Capacitive touch, has hardware interfacing datasheets (not propriety information only revealed to larger companys under NDA), has drivers for both the LCD panel and Touch panel for Linux - THEN we can talk (I'd be very interested as I still have time to change the design)... But do not waste my time with some random panel that will not even fit on the MDAC front panel that you've seen on EBay, one that undoubtedly has no hardware information / software drivers etc...

    I'm sorry to others here for the tone of my reply, but I've spent a huge personal fortune and time on this project and obviously I don't appreciate being second guessed in a "shit staring" manor - there was no positive point to the question, its only purpose I can see is to cause trouble.

    To "Finance" the software development of this LCD panel for the MDAC2 project, I'm having to spend 2 weeks in China / HK as an "Adviser" introducing a local European company to Chinese vendors / production. This is 2 weeks away from Renata, Pups and the comfort of my lab so I can "deliver" important finishing features to this project... Then I get questioned about the cost of various parts...

    I detest the idea of having to spend anymore of my life in China, but I'm single track minded in delivering the very best possible design, even if I have to "sell my soul" by travelling to Asia... :(

    There is an upside to the trip apart from the "Direct" benefit of having the software developed for the MDAC2 Touch panel - that while I'm in China I also plan to visit the Detox chassis CNC vendor...
     
    ti33er, Rune, paulski and 1 other person like this.
  14. JohnW

    JohnW pfm member

    I'm planning on visiting the CNC vendor during my pending trip to Asia... so the Detox is still on the cards but in many ways has been superseded by the integrated Detox technology option in the MDAC2 / FDAC. Having the Detox internal to the DAC allows added advanced "Modes", at the expense of the ultimate RF isolation offered by an external unit.

    In essence, the external Detox will offer the best RF isolation - while the internal Detox option offers the best decorrelation performance. The Detox circuits are enclosed in separated screen enclosures on the DAC PCB - but there RF isolation is not as great the "Slab" of aluminum used on the external Detox.

    I find that the Detox Decorrelation offers greater sonic performance enhancement over RF attention so on balance internal Detox should offer greater sonic improvement.

    I'm being deliberately coy about the advanced Detox modes as so not to give too much away ahead of release - but also as a "nice" surprise... :D After MUCH work and expense and many wrong directions I'm now VERY happy with path of the MDAC2/FDAC design - many uniquely developed technologies have come together to make a very unique (and hopefully great) sounding DAC :D

    Most importantly I "Feel" the DAC is now correct - and "feeling" is a very important guide to a designer!
     
    HarryB and amershamman like this.
  15. russel

    russel ./_dazed_and_confused

    I think you have to look at it from someone who has given you money to do a job, you talk about "your IP" well the people that funded you might not think that way, if you have used us as an r&d funding source it might have been better to state that you would keep all the information and selling rights yourself, it's not normal for investors to be shut out. Secondly the amount of feature creep on this design is excessive, I signed up for an MDAC2 which I thought would be a board replacement, I am quite happy with the current UI and features I have a PC connected to it so I don't need or want to watch HD films on it, I am puzzled how a DAC has morphed into what is basically a home entertainment system.

    The project is now so expensive I have to consider whether it best to just write the whole thing off and I suspect a lot of other people might feel the same way, yes you may have a truly wonderful product but it's not what I signed up for, I wanted something that would address the design compromises of the MDAC, not add very expensive features I didn't ask for and don't need. You seem to forget to are dealing with individuals not corporate customers with deeper pockets. You have made something you wanted, not what your customers wanted which is why you are getting a hard time.
     
    JTC, Jason_PFM and HarryB like this.
  16. gints

    gints pfm Member

    I wanted something more than just 'better mdac'.
     
    Rune likes this.
  17. Stunsworth

    Stunsworth pfm Member

    It was acknowledged at the very beginning that the design would be John’s and he would be free to make commercial use of it once the boards had been supplied. People didn’t have a problem with it then and I don’t have a problem with it now.
     
    davidjt, Rune and Bob L like this.
  18. sq225917

    sq225917 situation engineer

    Seems like some people haven't quite grasped the moving target nature of the project and expected it to be fixed at the point they chipped in.
     
  19. killie99

    killie99 pfm Member

    I think some people have failed to grasp that nigh on 6 years down the road and multiple times the original cost estimate is not what any reasonable people signed up for.
    If there had been any inkling of that being the time scale and cost I would imagine the number of people signing up would have been somewhere close to zero.

    This whole project has turned in to John's hobby horse with scant regard for the people who have invested an awful lot of money and for the 4th (or is it 5th?) year in a row we're being told 'it'll be on show at Munich'. I'm afraid I can't share any optimism or enthusiasm for this car crash of a project.
     
    HarryB and kennyh like this.
  20. clivem2

    clivem2 pfm Member

    Even Detox.....it was to be a quick earner for John to help with fund the bigger projects and at the same time rapidly jump on the USB reformatting bandwagon plus do it better than the other options.

    That ship has sailed. John had the money, I've no idea whether his development costs were covered by the deposits.
     
    HarryB likes this.
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