Discussion in 'DIY' started by JeffYoung, Sep 29, 2019.
Some better closeups:
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
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.
Mad skills, @JeffYoung. Kudos.
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....
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.
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!
Kicad files (including CSV BOM):
Let me know if you have any issues.
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.
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
Also - could you link/upload the schematic if you have it readily available? Thank you!
EDIT - the schematic is here - https://www.diyaudio.com/forums/pass-labs/300060-pass-hpa-1-a-8.html#post5924169
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:
2x 25V (2,25A)
cost: 54,50 EUR/pc
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