Neurochrome HP-1

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Cspirou, Oct 26, 2016.

  1. Cspirou

    Cspirou Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    762
    Dislikes Received:
    4
    Trophy Points:
    93
    Location:
    Irvine,CA
    Edit: Tom (@tomchr ), the designer, has circumvented the embargo and has posted himself |\/|

    So I was wandering on the page of one of my favorite DIY suppliers when I see this:

    http://www.neurochrome.com/product/hp-1-ultra-high-end-headphone-amp/

    I like that he offers options from the PCB alone all the way to a fully assembled product. Although one thing that I think is a bit odd is that the fully assembled PCB is $850 and the chassis is $200. That adds up to $1050, however the fully assembled product is $2200$1499.

    Anyway, he has a really good reputation for his amp builds so I am curious how he approaches headphone amps. I thought about buying the PCB and adding it to my pile of unfinished projects, but at $200 I can't just let this sit around.

    Some additional info:

    http://www.neurochrome.com/hp-1-ultra-high-end-headphone-amp/
    • [*]Fully optimized 4-layer circuit board.
      [*]Total harmonic distortion: 0.000032 % (200 mW, 300 Ω).
      [*]Total harmonic distortion: 0.000050 % (200 mW, 32 Ω).
      [*]Total integrated output noise: 1.0 µV RMS (A-weighted, 20 Hz – 20 kHz).
      [*]Output power: 3.0 W (32 Ω).
      [*]Output power: 450 mW (300 Ω).
      [*]Gain selectable (+6, +12, +20 dB) by front panel switch to accommodate a wide range of sources, including smartphones, tablets, DACs, and CD players.
      [*]1/4″ phone and 4-pin XLR output connectors.
      [*]Balanced (XLR) and unbalanced (RCA) inputs.
      [*]±0.1 % tolerance Susumu RG-series resistors used in critical parts of the circuit to ensure the best possible performance.
      [*]All signal switching is accomplished using relays with gold plated switch contacts.
      [*]ALPS RK097 volume control potentiometer.
      [*]Well filtered switching power supplies followed by onboard low noise linear post-regulators ensuring the highest power supply performance.
      [*]Protection against DC voltage on the amplifier output.
      [*]Integrated mains soft start and 320 Joule surge suppressor.
      [*]ON indicator emitting a subtle and pleasant blue glow.
      [*]International mains voltage compliant (85 – 264 VAC @ 47 – 440 Hz).
      [*]All aluminum chassis made in Canada.
    Judging from the ridiculous THD numbers and the measurements he has posted, it looks like the ultimate expression of an objective amp. Audio pros and reviewers would probably be interested in an amp like this.
     
    Last edited: Oct 28, 2016
    bazelio, brencho and ultrabike like this.

  2. Jh4db536

    Jh4db536 Friend

    Friend
    Joined:
    May 25, 2016
    Likes Received:
    389
    Dislikes Received:
    1
    Trophy Points:
    63
    Location:
    Los Angeles
    $200 for a bare PCB is a lot to jump in blind. I didn't find there to be a lot of information on the circuit, topology, or BOM in the product details page. It's about $650 to make a complete amp PCB, components, chassis. It kind of resembles a Jotun amp, but more expensive.

    Projects like these always make me curious as I'm always open to new ideas from reputable designers. I'd be interested in donating my soldering hand to a sbaf owned loaner.
     
    Cspirou likes this.
  3. Armaegis

    Armaegis Friend

    Friend Contributor
    Joined:
    Sep 27, 2015
    Likes Received:
    2,097
    Dislikes Received:
    0
    Trophy Points:
    113
    Location:
    Winnipeg
    No pot between gain stages? I'm sold :cool:
     
  4. Cspirou

    Cspirou Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    762
    Dislikes Received:
    4
    Trophy Points:
    93
    Location:
    Irvine,CA
    Maybe on the outside but the inside seems totally different. For one I don't think it's a discrete design. Besides his tube amps everything else he makes uses opamps or power opamps and I wouldn't be surprised if this is opamp based as well.
     
  5. Hrodulf

    Hrodulf MOT: Sonarworks

    Friend
    Joined:
    Sep 28, 2015
    Likes Received:
    863
    Dislikes Received:
    2
    Trophy Points:
    93
    Home Page:
    Getting a bit of a solder boner here. Prolly will build one for the office.
    • ON indicator emitting a subtle and pleasant blue glow.
    ^^ I'm dying.

    MTOC's face when he beholds dat heavenly crosstalk.

    [​IMG]
     
    Last edited: Oct 27, 2016
    jowls, Huxleigh, Pyruvate and 8 others like this.
  6. Cspirou

    Cspirou Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    762
    Dislikes Received:
    4
    Trophy Points:
    93
    Location:
    Irvine,CA
    For such a high end design I am a bit surprised he goes for the smaller rk09 instead of the rk27 ALPS pot. Also curious about the additional filtering he does to the SMPS.
     
  7. Hrodulf

    Hrodulf MOT: Sonarworks

    Friend
    Joined:
    Sep 28, 2015
    Likes Received:
    863
    Dislikes Received:
    2
    Trophy Points:
    93
    Home Page:
    Resistance tolerance for both is quoted 20%, so they might end up being equals. I'm more interested in the principal schematic. The guy has a knack for getting the best out of IC's, but so far it looks like a The Wire Deluxe. Also I might've stuck to a fully balanced topology (the pot looks two gang).
     
  8. Cspirou

    Cspirou Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    762
    Dislikes Received:
    4
    Trophy Points:
    93
    Location:
    Irvine,CA
    True, but channel imbalance is generally worse with smaller pots at low volumes. Unless he's using a linear taper and is doing some sort of fake log arrangement.

    I hope his page will fill us in on more details.
     
  9. Hrodulf

    Hrodulf MOT: Sonarworks

    Friend
    Joined:
    Sep 28, 2015
    Likes Received:
    863
    Dislikes Received:
    2
    Trophy Points:
    93
    Home Page:
    Betterer pix.

    [​IMG]

    [​IMG]

    What do your elven eyes see?
     
  10. ultrabike

    ultrabike Measurbator - Admin

    Staff Member Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    3,833
    Dislikes Received:
    5
    Trophy Points:
    113
    Location:
    Irvine CA
    I see expensive awesomeness.
     
    Last edited: Oct 27, 2016
  11. bazelio

    bazelio Friend

    Friend
    Joined:
    Nov 16, 2015
    Likes Received:
    2,166
    Dislikes Received:
    8
    Trophy Points:
    113
    Tom Christiansen (Mr. Neurochrome) is a very talented circuit designer and engineer. He is also very anti-audiophoolery. That is, he very much believes in designing for technical rather than subjective excellence.

    I've had many offline chats with him. FWIW.
     
  12. Huxleigh

    Huxleigh Wow, I made it this far without being a friend?

    Banned
    Joined:
    Mar 28, 2016
    Likes Received:
    937
    Dislikes Received:
    5
    Trophy Points:
    93
    Location:
    Somewhere dry
    Looks like the last unit is stock is currently selling for $1.5k. If it's as good as advertised, that's a more tempting price.
     
    Last edited: Oct 27, 2016
  13. ultrabike

    ultrabike Measurbator - Admin

    Staff Member Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    3,833
    Dislikes Received:
    5
    Trophy Points:
    113
    Location:
    Irvine CA
    Well I dunno about audiophoolery and stuff, but his design is sort of what I had in mind to make myself maybe one day.

    I'll be honest, in most cases what holds me back is the price tag (even DIY stuff). I do believe that usually a well design piece of equipment will yield great sound. But I also believe in reaching a balanced between performance and price. Specially for mainstream consumers (such as myself).

    I do not necessarily see boutique parts in his design, but $225 for a bare board seems a bit steep to me.

    In fact, the reason I was looking on making myself something similar to this, is to see if I can do it for $150 - $300, and have some fun while doing so, which might justify going over $100 as a real hobby.

    It depends on what one is looking for in the DIY arena. If $1k to $2k is fine, then I guess this is fine. But one can get something very nice with balanced I/O already for that range of $ already anyway. I mean the Mjolnir is already south of that, and the measurements there are not 1E-28%, but they are fairly decent.
     
    Last edited: Oct 27, 2016
  14. Walderstorn

    Walderstorn Facebook Friend

    Joined:
    Mar 20, 2016
    Likes Received:
    53
    Dislikes Received:
    1
    Trophy Points:
    28
    Location:
    Europe
    My eyes see that i know nothing just by looking at those pics ehehe, pots (ok i know what these are at least), capacitors, transformers, etc... oh i have so much to learn..and im always amazed by the knowledge most of you guys have.
     
  15. bazelio

    bazelio Friend

    Friend
    Joined:
    Nov 16, 2015
    Likes Received:
    2,166
    Dislikes Received:
    8
    Trophy Points:
    113
    It's 100 bucks more than a bare T3 board, for example. But I don't know what Tom's costs are, where he gets the boards printed, how many layers he has used, etc. It's mostly surface mount instead of through hole. I do have a sense for how much time he puts in to the circuit design and simulation as well as the board design, and I don't agree that $225 is steep. But no biggie there. Tom values his time at a particular rate, and it is what it is. Designing for yourself entails a different set of considerations IMO.
     
  16. ultrabike

    ultrabike Measurbator - Admin

    Staff Member Friend
    Joined:
    Sep 25, 2015
    Likes Received:
    3,833
    Dislikes Received:
    5
    Trophy Points:
    113
    Location:
    Irvine CA
    The bare board pricing depends on volume and margin. Like you said, it's up to the seller to determine those things. It's up to the consumer to pay it.

    I don't want to go into a discussion about pricing. It is very likely that Tom is pricing his wares competitively.

    For some his stuff maybe a bargain. For some it is not. Such is life.

    I will say this though. At least on paper and from visual inspection, he is providing a nice alternative.
     
    sphinxvc likes this.
  17. bazelio

    bazelio Friend

    Friend
    Joined:
    Nov 16, 2015
    Likes Received:
    2,166
    Dislikes Received:
    8
    Trophy Points:
    113
    You broached the pricing topic; I did not. Tom's strategy aside, I'm not entirely sure how the cost gets to $1.5K. $225 board, $200 chassis. OK $425 plus parts. EDIT: OK, I now notice posts saying it looks like $625 to DIY a complete amp. That sounds reasonable. Yeah, the assembled cost is a different issue, but I do consider Neurochrome to be a DIY platform.
     
  18. Cspirou

    Cspirou Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    762
    Dislikes Received:
    4
    Trophy Points:
    93
    Location:
    Irvine,CA
    It's a 4-layer PCB and a fairly big board. He also knows what he's doing when designing a PCB and deals with complex pours and other stuff that is way beyond me. Most DIY boards are much simpler and fairly stairfoward to reproduce. This one seems like it would still cost quite a bit if I had access to the gerber files.

    I'm sure a bit of the price is from proprietary knowledge but that PCB is no slouch.
     
  19. Cspirou

    Cspirou Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    762
    Dislikes Received:
    4
    Trophy Points:
    93
    Location:
    Irvine,CA
    It looks like there are 4 big elements along the bottom. Could be opamps. Also looks like it's fully balanced as well. Still very curious how he's dealing with volume with a stereo pot. Chips near the input XLR make me think there's an input buffer.
     
  20. Hrodulf

    Hrodulf MOT: Sonarworks

    Friend
    Joined:
    Sep 28, 2015
    Likes Received:
    863
    Dislikes Received:
    2
    Trophy Points:
    93
    Home Page:
    Where I come from this hardly is considered DIY. More like assemble yourself. You're providing the soldering service and some logistics management for the rest of the parts.

    If it ends up being a true reference amp then it's not a bad price, considering the competition. Tom also provides a very thorough documentation for his products, which is always welcome.

    I really liked what he did with the Modulus amp. The power output was a bit on the weak side, but sound wise I found it hard to fault. And that's despite some unaudiophile solutions.
     
    sphinxvc likes this.

Share This Page