New Nelson Pass ACA Kits on pre-order

Discussion in 'DIY' started by botrytis, May 11, 2018.

  1. nj pheonix

    nj pheonix AK Subscriber Subscriber

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    I have been eyeing an F5 build.
    Again chassis pre drilled tapped gets to half+ cost of the build.
    Pricing out a while back sourcing the DYI boards, bom , matched outputs , tranny was getting to be 800 or so (IIRC)
     
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  2. Pio1980

    Pio1980 AK Member Subscriber

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    I recently bought an expanded Aleph J clone from a great fellow AKer, fwiw.
     
  3. ReactiveLoad

    ReactiveLoad New Member

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    The F5 doesn't use matched outputs. You can try to match them if you want, but the diyaudiostore doesn't sell them matched .
     
  4. Robie

    Robie Live it or live with it. Subscriber

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    Eventually, once my skill set grows, I'd love to build an F5. Until then, my new Schiit Saga and unbuilt ACA amp have my attention.

    I know it may not be the best amp but I will guarantee it will be the best amp I've built thus far. ;)
     
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  5. ReactiveLoad

    ReactiveLoad New Member

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    33
    That's the whole point!
     
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  6. nj pheonix

    nj pheonix AK Subscriber Subscriber

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    I'm basing this on my memory (always an iffy proposition)
    IIRC I was conversing with 6L6 ( I think both here and on the DYI forum)
    I also think he has something to do with DYI store.
    Anyway , when I was considering , he suggested getting matched outputs. He put me in touch with a guy in Germany who sold me matched outputs. So, somewhere here is a set of matched outputs for an F5 (or maybe an F5 turbo?)
    Again IIRC, he seemed to feel this was the way to go and the project got mothballed unti (perhaps?) a later date. I had a handle on the build and then I got sidetracked. If I go forward:dunno:
     
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  7. ReactiveLoad

    ReactiveLoad New Member

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    Matching is desirable if it's possible, in theory, but there are subjective drawbacks some might say. Nelson doesn't think matching is all that important or even desirable. He specs either IR or Fairchild part sfor the F5 outputs, but he personally prefers the IR parts because the P channel part has a quick that lends some second order distortion, which in the F5 is preferable. 6L6 talks a bit about adding 2nd order distortion to the F5 through adjusting P3 in one of his YouTube videos. The biggest complaint about the F5 is that it's ruthlessly revealing. Having a little mismatch or imbalance in the amp may be subjectively desirable. I love the F5 because it's got a lot of possibilities to modify or customize to your tastes . Plus, it's not that much harder to build than an ACA, though it is more complicated to adjust.
     
  8. nj pheonix

    nj pheonix AK Subscriber Subscriber

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    Like i said, something I read (often the lead in to another rabbit hole) made me want one. I think the total build price and something else shiny that ate my disposable funds at the time, shelved the project.
    If you bought the pre drilled chassis, it looks like an easy build. I know in the interim I've read about the Aleph as well.
    It sort of muddied the waters (in my mind).
    Maybe it's just me but the terms customizable in building a from scratch amp seems odd .(in adding distortion).
    While I'm not hung up on distortion #s (I tend to work on and listen to tubes mostly)
    My thought process drifts to reproducing the input accurately.
    Adding distortion seems (to me) to be counter productive .:idea:
     
  9. 1108

    1108 Member

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    72
    The ACA will surprise you. It's really a nice sounding little amp.

    I was planning to build the F5 but build the Aleph J instead and I have started the M2. If you get through the ACA ok, you'll be fine with any of these. They really aren't much more difficult and they all have very active build threads.
     
  10. sachu888

    sachu888 Spare the tigers, kill me

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    We had a group buy few years back for F5. All boards were designed by my friend and a member here Omishra. It was a nice amp, but I like ACA more. Here is a link for the our builds https://www.hifivision.com/threads/diy-pass-f5-turbo-v2-initiated.28245/page-37
    We also had a GB for Jean Hiraga Le Monstre. It was also a nice amp with enough gain, chassis also provided by my friend. Here are some pics https://www.lencoheaven.net/forum/index.php?topic=20446.0
    One of the latest build here http://www.diyaudio.com/forums/solid-state/5462-hiraga-le-monstre-148.html

    Regards
    Sachin
     
  11. ReactiveLoad

    ReactiveLoad New Member

    Messages:
    33
    The F5 will get you .003% distortion without any matched outputs, but a lot of people, includuin myself, prefer more distortion with that amp. Matched outputs will probably get you lower distortion, but at a price. The cool thing about the complimentary BAGS and F5 is you can adjust it for microscopic odd order distortion or you can smooth it out for a good second order either positive or negative phase. It definitely has a clear effect and it's interesting to listen to what the distortion does. A dominant negative phase second harmonic definitely adds a depth and dimensionality to the sound. Positive phase is more forward and in your face, and the lowest possible distortion sounds extremely clear and detailed, but looses some of the depth of field effects .It's something to be played with because it will develop your taste and listening skills.
     

     

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  12. nj pheonix

    nj pheonix AK Subscriber Subscriber

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    Maybe when the bench clears I'll revisit.
    You're not by western Jersey/ Eastern PA are you?
     
  13. ReactiveLoad

    ReactiveLoad New Member

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    33
    Nope. Ohio here. I recommend watching Nelson's 2015 Burning Amp lecture. That's a much better source of info on the F5 than I am.
     
  14. nj pheonix

    nj pheonix AK Subscriber Subscriber

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    Ok thanks
    To the OP
    We sort of wandered off track
    My apologies
     
  15. Pio1980

    Pio1980 AK Member Subscriber

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    The added 2nd harmonic euphonics seem to "fluff up" sound and the sound field in theory and practice, but maybe more akin to adding reverb or other quasi-euphonic effects at the expense of ultimate fidelity.
    Another consideration is apparent dynamics and how that may relate to simplicity and feedback application. What makes some amps sound dead, dull, and lifeless tho "accurate", vs those that seem to impart (or pass) the lifelike verisimilitude of an in-person experience, because or regardless of simplicity/ complexity. On the second, I am reminded of the Stereophile review of a Muse One Fifty amp, I think most of us want something that does 'that', along with the other things that we prioritize.
    I'd like to think the Pass project amps do 'that', along with their other virtues within their power range.
     
  16. KKnight

    KKnight Active Member

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    +99
     

     

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  17. ReactiveLoad

    ReactiveLoad New Member

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    And your 10 year old would learn absolutely nothing buying some 10 dollar chip amp from Part Express.

    You talk down about the ACA calling it exactly what it is as if that's a bad thing. The Amp Camp Amp series is specifically designed for a kid to assemble in a day. That was the entire point of Amp Camp. It's designed to inspire curiosity and to develop understanding. If you can build and learn the ACA, you can understand why it does what it does and build on that. It's not meant to be a bargain on a great amp. It's ment to be a very cheap education in audio electronics. And if you're willing, the ACA can certainly be built out to achieve much better performance. It's just the first stepping stone and one a LOT of people want.

    Furthermore, I think developing understanding amongst the listening public does more to further the art of this hobby than the ridiculous $100,000 amps D'agostino is hocking .
     
    Last edited: Aug 11, 2018 at 12:15 AM
  18. restorer-john

    restorer-john Addicted Member

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    It's not very cheap, nor is it an education in audio electronics. It's rated performance is absolutely atrocious.

    It's a grossly overpriced, paint-by-numbers, toy amplifier with a guru's name associated with it. See it for what it is, not what you want it to be.
     
  19. 1108

    1108 Member

    Messages:
    72

    So what? Why do you care? Have you actually heard the amp? One ACA thread has over 5000 replies and over 1 million views. You won't find one unsatisfied buyer there.
     
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  20. 1108

    1108 Member

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    72
    Actually it's plus one. You and restorer-john.
     
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