A DIY version of the Pass HPA-1

Discussion in 'DIY' started by JeffYoung, Sep 29, 2019.

  1. JeffYoung

    JeffYoung Friend

    Friend
    Joined:
    Apr 11, 2017
    Likes Received:
    639
    Trophy Points:
    93
    Location:
    Ireland
    Some better closeups:

    finished1.JPG

    finished2.JPG

    finished3.JPG

    finished4.JPG

    finished5.JPG

    finished6.JPG

    finished7.JPG

    finished8.JPG
     
    • Like / Agree Like / Agree x 19
    • List
  2. dBel84

    dBel84 Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    2,236
    Trophy Points:
    93
    very nicely done. can't believe the amount of metalwork that you put into this project, let alone board design and implementation. you set a very high bar ! ..dB
     
    • Like / Agree Like / Agree x 1
    • List
  3. skem

    skem Friend

    Friend
    Joined:
    Nov 1, 2017
    Likes Received:
    1,826
    Trophy Points:
    93
    Location:
    People’s Republic of Cambridge
    Indeed... Ground planes on board look very impressive. I don’t know enough about the topic to know what to look for, but it seems fancy. ;)
     
    • Like / Agree Like / Agree x 1
    • List
  4. Senorx12562

    Senorx12562 Case of the mondays

    Friend
    Joined:
    Oct 26, 2015
    Likes Received:
    3,079
    Trophy Points:
    113
    Location:
    Bird-watcher's paradise
  5. Mikeyzen

    Mikeyzen Rando

    Joined:
    Jun 29, 2020
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Dominican Republic
    greetings all...i am new here, and my immediate reason for joining is to inquire about the possibility of buying a stuffed board for this amp, minus main filter caps and volume pot. if there is no such animal, is there anything close? i was tempted to buy a Pass Zen from a source like Ebay, but i an not convinced that it is a worthwhile choice..Help....
     
  6. Martigane

    Martigane Rando

    Joined:
    Mar 5, 2019
    Likes Received:
    50
    Trophy Points:
    13
    Location:
    Belgium
    Hi Mikeyzen,
    Not sure if you are still looking around, but the diy HPA WHAMMY full kit is available on diyaudistore.com.
    It is basically a scale down of the HPA1 (but still has plenty power for 99.9% headphones), and has op amp instead of discrete transistors, which lets you swap op amps around for best synergy and upgrades.
    I built mine 1 year ago and it measures and performs great.
     
  7. Tennstrong

    Tennstrong Rando

    Joined:
    Aug 31, 2020
    Likes Received:
    7
    Trophy Points:
    3
    Location:
    Vancouver
    Hey Jeff,

    I'd be interested in (and be very very thankful if you can provide) the kicad/gerber files if you still have those around, if you happen to have the BOM as well that would be fantastic. I saw the WHAMMY, but I am really intrigued by this specific design. Seems to be the class where I will definitely notice a (possibly significant) improvement over my current amp, and somewhat feasible leveraging online laser cutting services & my connections with local cnc operators for the chassis. At the least it will provide me some reference for future hp amp testing/building which I am just as happy about. Any other info like chassis dimensions/port locations would be appreciated, but really just providing the files & possibly BOM (if it's not overly evident for certain components) would be fantastic and should be enough.

    Thanks in advance!
     
  8. JeffYoung

    JeffYoung Friend

    Friend
    Joined:
    Apr 11, 2017
    Likes Received:
    639
    Trophy Points:
    93
    Location:
    Ireland
    Kicad files (including CSV BOM):

    Let me know if you have any issues.

    Cheers,
    Jeff.
     

    Attached Files:

    • Like / Agree Like / Agree x 10
    • List
  9. JeffYoung

    JeffYoung Friend

    Friend
    Joined:
    Apr 11, 2017
    Likes Received:
    639
    Trophy Points:
    93
    Location:
    Ireland
    The Darlingtons in the PSU (2SB1259/2SD2081) can be a bit hard to source. I think DigiKey has them in stock at present though.

    For the Toshiba JFETs "punkydawgs" on ebay is my go-to source. You can also use Linear Systems' JFETs from the DIYAudio Store.

    Everything else should be pretty easy to find.
     
    • Like / Agree Like / Agree x 2
    • List
  10. wrestler

    wrestler Acquaintance

    Contributor
    Joined:
    Mar 12, 2017
    Likes Received:
    32
    Trophy Points:
    18
    Location:
    SF Bay Area
    What is the model id of transformer? Unless I am missing something, the BOM doesn't include the transformer. I can see the brand is toroidy
     
  11. wrestler

    wrestler Acquaintance

    Contributor
    Joined:
    Mar 12, 2017
    Likes Received:
    32
    Trophy Points:
    18
    Location:
    SF Bay Area
    Last edited: Jan 4, 2021
  12. JeffYoung

    JeffYoung Friend

    Friend
    Joined:
    Apr 11, 2017
    Likes Received:
    639
    Trophy Points:
    93
    Location:
    Ireland
    The transformer I used is 120VA with 3 secondaries: 2 @ 25V/2.25A and 1 @ 12V/0.5A.

    The following is the quote I got from Toroidy (although that was some time ago now):

    Audio grade transformers:
    TS 120VA
    PRI: 230V
    SEC:
    2x 25V (2,25A)
    12V (0,5A)
    cost: 54,50 EUR/pc​
     
    • Like / Agree Like / Agree x 2
    • List

Share This Page