R2R DA M1 Ultracap powered build

  1. bballas
    uuuppps!:ksc75smile:
     
  2. abartels
    I really think if adding EVERY component used, all small parts (like anti vibration grommets etc.), building costs will come close to $3000
    And that is materials used ONLY. Keep in mind that if going commercial, you should count assembling costs as well as a few percent profit.........

    Also keep in mind that most commercial designs have a factor 5 to 10 between build-cost and end-user price. This makes very clear in what kind
    of price range this dac would have to operate.....


    Smaller versions with smaller psu's can get cheaper, as do SE versions, or FIFO-less versions with I2S-input only, or USB-input only.
     
  3. bunkbail
    Have you guys ever heard of LessLoss Echo's End? It uses the $400 Soekris dam1121 single R2R module and retails the whole dac at $5342. Just look at its internals. I mean, what you guys are doing here is far more impressive than this overpriced piece of snake-oil trash.
     
  4. abartels
    I wasn't aware of the Echo's End, thanks for showing us :) The only good thing is the wood he uses, hahahahaha.
    Soekris OEM isn't bad at all, but it's nothing special. $5K+ that's a lot of cash...... and indeed WAY overpriced.

    Yeah, I am VERY sure our designs do sound a little different :)


    Cheers :beerchug:
    Alex
     
  5. coinmaster
    I want to believe this dac is good, the designer in me has a hard time believing that all those super caps can't be simplified with a super-regulator. At the current the dac is running at, that much capacity should be practically pure DC as long as the caps are placed as close as possible whatever it is supplying. But the same thing applies to a super regulator. I don't see the difference other than cost.
    Have you tried using a super regulator instead?
     
  6. abartels
    I think I don't overreact when saying that I tried A LOT the last 40 years or so.


    If you can find me a superreg which has an infinite PSRR, and a solution to galvanic isolate that reg's
    output from it's input, for example, then I will look into it, promised.........
     
  7. coinmaster
    40 years-shmorty years, the entire audio electronic industry is lazy and/or stuck in the past.
    Technology and understanding has improved yet everyone still uses ancient standards.

    I'm not directing that statement at you but the amount years worth of effort means little in a field where most people lack innovation, creativity, understanding, or aren't up to date on the times.

    Even over at the diy-audio forums I find myself bored with their creations, it's just the same old stuff.
    There's a few people that stick out among the crowd like wavebourne, john broskie, nelson pass, and a few others. Unfortunately they aren't in the official industry, at least not on a scale that they deserve.

    I like to think of myself as another that sticks out among the crowd, I've developed amps using out of that put anything I've ever heard on the market to shame at a fraction of the cost.
    It's all about being creative and thinking outside the box and actually trying to solve the technical shortcomings of the specific technology you are using to reach a specified goal.

    Something most people do not do unfortunately.


    You mentioned you desire to start your own company.
    I too am looking to start up my own company, maybe we could team up or something :L3000:

    If people like woo-audio can get away with using ancient designs in shiny cases and still manage to rank in the dough I'm sure we can do it :p


    In any case super reg does effectively have infinite psrr for any practical use if you do it right.

    You're supposed to feed it with a pre-reg, aside from the regulators own psrr the pre-reg makes the entire regulators psrr practically infinite since it's feeding the regulator with pure dc, you could make the ultimate pre-reg with a few of those ultra caps and a cap multiplier, just be careful of the current th
    Or if you wanted to go into extreme overkill-land you could use another super reg as a prereg but that's just silly, although I do like my overkill.

    Here is an example of the performance at the output of a super reg at 3 amps DC draw and 2 amps of 20khz swing, the impedance should be flat up between 100hz-100khz with a slight increase below 100hz if I recall.
    I totally forgot how to run an impedance simulation in LTspice, it's been a while.

    keep in mind the higher the current the worse the performance is.
    You won't need anywhere near this kind of current draw so the performance will be much better.
    I chose this example to show you that even at high currents it performs this well.

    The performance can also be improved with faster opamps but then you need to deal with quelling instability.

    Green = voltage
    Blue = current
    [​IMG]
    The pre-reg in this example has about 4v on ripple on it, I would need quite a bit more parallel capacitance to get raw DC at these currents, but I mean does it really matter? Look at that voltage swing at the output.

    The super reg has non existent output impedance in any practical use if you do it right. I'm talkin' low micro ohms.

    I don't understand what you mean by galvanic isolation between in the input and output of the reg, just feed it with an appropriate transformer.
     
    Last edited: Oct 10, 2017
  8. abartels
    Thanks for your interest and explanation Colin. I am aware of the pro's of superregs, I do like the almost none existant output impedance, that's for sure, but that on its own also isn't the holy grail.

    Calculations and measurements are very important, but, you do know, as I know, that our ears are very sensitive measurement tools too. Like you described harmonic distortion of tubes,
    against IMD or even worse, I really would like you to try these ultracap designs in source devices.

    Build it and compare it with your superreg designs. Just listen to the result, and report back. A simple test, a 5V or 3.3V psu, need only 4 ultracaps and some simple electronics, try feeding
    an important stage in source device like tcxo's, fifo, dac voltage rails, etc. Listen to it and report back.

    Btw, I myself have 30yo DIY mosfet power and pre amps, nfb, class-A. See link below for the power amp's (smaller) successor....
    http://modusaudio.com/spa01.html
    The guy behind Modus, Richard, he's a very good friend of mine which designed my power amp and pre amp. With him I started an audio company in the nineties, we had a very good DAC.
    Sadly we didn't manage to keep the company up and running......

    I am not planning to start a company, I even have some bitter leftovers to process from my last, computer/ICT related company.....
    If I am going to start some sort of audio company, it will be very low profile, and probably source-related only.

    Do yourself a favor Colin, as an open minded person who is into new designs and thoughts, try those ultracap designs and give them a good audition.


    Btw, Richard's words after listening to :alien:ΛΓienStreamer

    "This is the absolute best 4D sound presentation I have ever heard, that's for sure......."

    And that even was with output transformers with magnetized cores :muscle:
     
  9. bballas
    AD2A1E56-AE5D-4556-AD8C-C96446F44167.jpeg monyo dac inside:
     
  10. coinmaster
    I agree, the best sounding stuff is usually not the best measured. Unfortunately the amount of ways to build an amp with the design goal of it "sounding good" that isn't based on theory, is infinite.
    Which is why I like to set design goals using theory and then tweak in imperfections afterwords. It makes for a more refined design this way anyway.

    I would like to try the ultra caps but they are ultra expensive :p which is why I was hoping you would try the super-reg so you could tell me how they compare. Believe me when I say I am interested to know if the ultra caps are an improvement.
    I still need like $5,000 worth of equipment to officially finish off the R&D of my amplifiers, my desire to avoid proper lab equipment has ended up costing me more then I would have spent otherwise and one-off pcb manufacture is expensive as well.
    I can't afford to build your dac at the moment.

    Yeah I hear it's difficult for an amplifier company. Thankfully unlike the nineties I have ebay and amazon for initial distribution, websites are easy to make, and I have internet forums and plenty conventions each year to market the product.

    I'm keeping my initial expectations low, but I'm hoping the merit of the products will carry itself. I've never heard a big name product that sounds anything close, the entire industry is stuck on old standards. My goal is to hopefully move things forward a little bit.

    Other than amplifiers I'm looking into speaker tech as well such as planar/electrostatic hybrid. or more likely ribbon/electrostatic hybrid headphones, which in theory should have merit yet I don't think anyone has done it before.
    Also looking into standard ribbon tech because of its obvious advantages although the most likely reason that it is not a commercial headphone tech is due to its fragility.
    Also DML tech which may be the easiest to R&D.

    But that doesn't even scratch the surface, stuff like conversion to high impedance output stages and other theoretically superior standards that no one seems to be taking advantage of could make things very interesting.
    Unfortunately this all costs time and money. Time I have, money I don't :frowning2:
     
    Last edited: Oct 11, 2017
  11. abartels
    @coinmaster

    Yeah, my design of course also is based on theory and took me a lot of hours to accomplish... Lots of brainstorming..... drawing, calculating, measuring etc.
    And tweaking afterwords is inevitable :)

    For testing purposes you can buy used ultracaps in China which won't break the bar. When using a taobao agent, like taobaotrends, you pay less than $2 per piece
    for those 100F 2.7V powerstor ultracaps, and that is including shipment.


    From experience back in 1991, which was an economic recession too, I can tell that, without the existence of the internet, I had to write letters to audio companies
    to get their interest in our product. I wrote 100 letters to the best Audio firms in The Netherlands, including some importers. From the 100 firms I wrote to, 4 already
    went bankrupt before they even received my letter, and 4 others were in severe weather which in the end resulted in 92 "potential customers".
    We visited 88 firms of the 92......... which alone was a HUGE result. Everybody was very interested in our product, a DAC. Our direct competitor, soundwise, was
    the most expensive Mark Levinson dac which was about HFL30.000 which is about $16.000
    Finally we had to seize our company because of the lack of investments. The product was perfect, our commercial inputs were great, but we couldn't get the money to start.
    We both end up with debt. That is how it can go.

    There are very good designs on the market, and some of them do sound marvelous. Not sure with what kind of source and speakers you listen to your amps and compare
    them with others. There's one thing I learned during my Audiophile existence, never say never. The most expensive Accuphase monoblocks 30 years ago didn't sound
    as good as my own amp, but to say all the others amps were "old" or "outdated" designs, and mine was best, hmm, that'would be a brute statement.


    Ever heard a Audio Research GS150 poweramp? Sounding bad? Not think so...at least, that is what I think. So you say your tube amps sound better? :)

    @bbalas

    Monyo dac, never heard of it, have a link?
     
  12. bballas
    you just joking right?my diy monyo dac dont have any link.
     
  13. coinmaster
    I never claimed my amp sounds "the best", it's arrogant to state that when I have only heard a finite amount of amplifiers.
    I only said they are the best that I've heard, although I've heard quite a bit and considering how much they cost to make compared to the insane cost of some of the commercial stuff I've heard that didn't sound even in the same league as mine, I'm honestly disappointed in the commercial audio industry.
    The average person is not even aware or able to imagine what real audio can sound like. Ipod and cellphones are the standard, that is the big shame here I think.

    Which is mostly the reason I want to build my own company, or at least sell some amps. It's an easy exploit in an industry that has remained mostly stagnant for decades.

    I've seen enough schematics from very high end commercial and non commercial designs to know that the average "high end" product is just...average.

    Take the KGSSHV for example, It's supposed to be some top end headphone amplifier and it's essentially a transistor cascade into a push pull output stage if I remember correctly.
    I mean seriously dude anyone with a reasonable understanding of analog design could come up with that, how bout being creative.

    One of the issues I have with most designs I see is that people don't even try to solve the inherent shortcomings of the design, at least not creatively. It's just a giant copy paste.
    NFB is the lazy mans way out. I don't even use it.

    I'm not saying old and/or typical designs can't possibly sound really good, but I certainly don't consider them high end and in my experience they just aren't up to par.


    I design exclusively with the premise of using unique and out of the box concepts, or at the very least something that hasn't been before much or at all.

    I use LTspice as a first measure of conceptual design, I've gone through countless concepts and managed to come out with about a dozen that I deem worthy enough to build.

    Although there is a particular input stage I have designed that I am particularly fond of, from an engineering perspective it's basically near perfect, aside from biasing the tubes with a built in algorithmic curve averaging system or something I can't think of a way to improve it, with the goal of clean linear amplification using tubes as the goal anyway.

    I've had a few prototype demos up and running and it sounded celestial, unfortunately it's annoyingly complex to build and my sad excuse for power supplies keep crapping out on me and taking out my prototypes with it, or vice versa.
    Hence why I'm in dire need of new equipment.
    I've also got a few output stage designs that read 0% distortion (technically like 0.0000000005% or something) in LTspice.

    The results remain consistent even when using mismatched components and adding any reasonable amount of parasitics into the design so they are legit. In practice I doubt it will be that good due to the "if it's too good to be true" rule of thumb but in my experience spice results are pretty accurate if you apply realistic parameters and results from proven designs show the typical 0.001% and things that they are claimed to be, so simply via trend and comparison the output stages I have are superior, whether or not it will be audible is another story, I haven't built them yet.
     
    Last edited: Oct 11, 2017
  14. kevin gilmore
    quote
    Take the KGSSHV for example, It's supposed to be some top end headphone amplifier and it's essentially a transistor cascade into a push pull output stage if I remember correctly.

    actually its a folded cascoded current mirror driving a grounded base gain stage with a current sourced emitter follower output stage.

    I would like to see what you would come up with that can swing 1.8kv ppss. That and the kgsshv is now 10 years old and has been replaced with something simpler and more effective.
    current production solid state parts that do these kind of voltages are hard to find these days. And tubes that can effortlessly swing these kind of voltages are also hard to come by.

    I understand the switching of capacitor banks, but how to make the switching glitchless, and the resulting regulation after that also bumpless seems very hard.

    in any case my GRLV power supply is at least 2 orders of magnitude lower in noise than what you have shown.
     
    Last edited: Oct 11, 2017
  15. coinmaster
    Yeah sorry it's been a while since I saw the schematic.

    For starters a current source emitter follower is well proven to be a less than optimal way of transferring the audio signal into a load. It's great in theory, when there is no load. There's a variety of ways to improve this using different types of feedback and feedforward techniques.

    Using a simple cascode follower as well would allow for high voltages and give better linearity and lower heat at the same time.

    I don't have any special issue with the amplification stage since swinging that kind of voltage cleanly can be troublesome and I haven't done too much research into alternative methods of that nature since it isn't my area of interest, at least not until I start building ES amps.
    I think I had an interesting potential concept or two stashed away in my archives somewhere, it had something to do with inverted triode operation or something, I forget.

    The KGSSHV was just an example, it was the only schematic I had recollection of. What is their latest one called? I want to see the schematic.

    Never heard of it. Is it cheaper to build then jungs? Anything better would be overkill of overkill I think unless it is cheaper :p I mean it's not like you can hear nano volt variations as it is.

    I think if the super cap power supply actually does sound better it would be due to its imperfections not it's superior performance.
     
    Last edited: Oct 11, 2017

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