SicPhones (Kickstarter): Zen-style class A amp with Silicon Carbide JFET

  1. nikongod
    Quote:
     
    I thought NP had patents on the floating bias CCS. 
     
    From the other post, agreed there is no such thing as no feedback, but so many people use the term to mean global feedback. There are so many types of feedback after all. 
     
    Quote:
     
    How does the Tao work? It is everywhere, and nowhere. He who talks about it the most knows the least. 
     
    "Zen" amplifiers are simply amps that are very simple. They are reduced to the absolute minimum of parts. This is in contrast with more common "more complicated" designs. 
    Both schools of design have their advantages and disadvantages.
     
    Zen amps are easy to understand - with only a few parts someone with a bit of electronics knowledge can "walk around" in the circuit, and see how things work quite clearly. Ask a "zen amp" builder to explain how his amp works and its easy! The disadvantage is that they don't usually have much (if any) global feedback so to get good SQ they need to use very specific parts - thus the funky transistors. Even with great parts they still dont usually put up measurements as good as more complicated designs, but there is still a certain sound that they often make - a lot like simple tube amps. 
     
    More complicated amps are much harder to "walk around" inside the schematic. Ask 95% of the people who have built a B22 to explain how it works. They don't know - just put the parts in and pray. The advantage to more complicated amps is that they usually design around feedback which allows the use of "who really cares, fix it with feedback" parts. Considering that the world in general is a "who really cares, fix it later" kind of place these days its a lot easier to find parts for this kind of amp. The disadvantage is that when you really look at it, your using feedback to polish a turd. 
     
  2. qusp Contributor
    yep, he has patents, but when has that stopped people from trading on his names?
     
    indeed, only zen v8 and 9 start to get a bit more complex. I took zen as referring to ZV1, or at least before zv4 where the aleph type CCS was starting to be explored. ie a simple CCS, not an actively modulated, dynamic CCS. I have the parts collected to build ZV9 including the lovoltechs, but havent gotten around to it just yet, I commandeered the heatsinks for another higher power class AB project, took me a little while to get my head around the SEPP too
     
    simple circuits have a particular sound, very nice to have as an option and ive enjoyed building them, great articles too, but I find they can be more subject to system synergy and the balance is more easily upset.
     
  3. zzffnn
    Quote:
    Are you referring to me when you said "He who talks about it the most knows the least."? What is the point of this phrase and is it relevant to our discussion here?
     
    I acknowledged on my 2nd post that "I do not have knowledge or skills to DIY........", meaning I know "the least".
     
    When I said "Zen-style", I was quoting designer's communications with 6moons. They used the word "Zen-style" for simplicity. I quoted them on that. Whether the actual amp is "Zen-style" remains to be determined.  
     
    When I said "constant current source", I was quoting Tyll / Innerfidelity.
     
    In comparison to reference to "Tao", I appreciate more specific/meaningful comments such as those offered by qusp:

    "no you have misunderstood, the constant current source in the Zen amp biases the output fet, which has local feedback and the amp has an output Z of 1ohms. having an output impedance of 1ohm and being a current source are mutually exclusive; a current source by definition has very HIGH, in the ideal infinite impedance. in Zen the current source does not drive the output, the fet does. the current source is between the positive rail and the fet, the fet drives the output".
     
  4. nikongod
    Quote:
     
    No, just Zen & the tao in general. 
     
  5. zzffnn
    A bit off topic here, but having a patent on "floating bias CCS" does not grant you right to everything related to "floating bias CCS". A patent's coverage is limited to the EXACT wording of its claims, not a single word more. Trust me on this as I am a patent agent who works on patent applications everyday. Someone can make a novel improvement on "floating bias CCS" and get a patent, as long as such invention is novel, non-obvious and distinctively/clearly claimed.
     
  6. qusp Contributor
    zzffnn: nah nikongod doesnt really play like that, I admit I also briefly personalized that comment myself before dismissing it, though at times like many here and in life i've been guilty of it. the internet makes it easy to be an 'expert'. Hes not a stranger to a cutting comment, but hes not usually that subtle =P
     
  7. qusp Contributor
    Quote:

    not the wording, but the circuit. given the man has won similar disputes against texas instruments for the super symmetric feedback patents when they used derivatives in some of their opamps, i'm pretty sure novel circuits can be defended, particularly if accompanied by matching trade names
     
  8. zzffnn
    Quote:

    Well legally, wording of patent claims is as important as the technology. I was a scientist who thinks technology is everything, then I came to this patent law world and saw how lawyers paid by big companies played around wording and laws. It may not be crystal clear what is novel & non-obvious regarding patent wording/claims (which are usually drafted to be as broad as possible in an application, but have to be limited later on to be a granted patent). Some have to go to an appellate court to fight for wordings of patent claims.
     
  9. bidoux
    The thread lacks a schematic, that is all I can think of.
     
  10. qusp Contributor
    Quote:

    agreed
     
  11. sr20det510
    Steve Guttenberg just published an article on Cnet, "An awesome-sounding headphone amplifier Kickstarter project"
    Amp sounds as if it is amazing piece of equipment for the $279!
     
    "The clarity is beyond, far beyond what I've heard from any other under-$1,000 amps, so if you crave sonic purity from your headphones, Colin Shaw's Sicphones amp is highly recommended."
     
    Think I'm ordering a fully built amp : )
     
    Has anyone else used one?
     
  12. zzffnn
    ^ You know Mr. Guttenberg is probably not very respected among some objectivists. However, some impression is better than none I guess.
    To those experienced DIYers, can you estimate rough cost of all the parts (do they worth about $229)? Can those parts be easily used in other projects (in case a person has buyer remorse)? Thanks.
     
  13. qusp Contributor
    how can we possibly suggest a value with no schematic and no detail of what power jfet parts are in use?
     
  14. zzffnn
    Sorry, I could not find the needed details. I agree that it is very hard to guesstimate a cost range. 
     
  15. longbowbbs
    Sicphone Amp is in the house.....
     
     
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    Bass monster. Solid build and pairs up very nicely with the Audioquest Dragonfly.....[​IMG]
     

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