Amp Camp Pre+Headphone Amp - ACP+

Interesting. Wouldn’t that mean I’d have to unplug my speakers when I just wanted to listen to headphones, though? There’s only one pair of speaker outputs

EDIT: oh, I see. It assumes you’d put it in a box with a switch. Not sure I’d want to add an extra connection in there
 
Last edited:
The ground plane is completely empty, except for the conductive mounting holes to bond the circuit PCB to it via the screws. This makes it quiet and suitable to be run with no chassis. It's pretty neat.

Anything you seen the ground plane in the edge-on photo is actually refections from the circuit PCB. It is mirror smooth.

Awesome pictures.

That looks great
 
What a build!!!!

I've been waiting almost a year to build ACP+—ever since missing out on BA last year—I couldn't make it at the last minute. The ACP+ open chassis-less design seriously belongs in the MOMA design store. I still haven't built it—but my 10 year old daughter DID! Obviously with my oversight. I didn't solder a thing—except we broke a mosfet leg and I did step in to repair that—didn't have extras—otherwise it's all her! She had a great time—we built it over a couple of days...(All color decisions—including the yellow "pants" on the LED leads are hers). Oh—and yea, she didn't need any magnifiers to do this—uh—WOW, kids. We looked a data sheets and tested the only 2 J113s I bought (gah!)—turns out they were a match.

Had a little drama with the DC jack and the PSU brick only realized at the critical payoff powerup moment—It would seem that we have a perfectly packaged PN correct brick per Nelson's BOM—that is internally center Neg! IDK. (DC jack from BOM is 2.5mm, PN should be PJ-037A [digikey CP-037A-ND] for 2.1mm. Sorry Nelson!). Took a minute and some 6L6 to figure it all out—mid flight for him! DEDICATION :D. Hardwired the leads in the end and wrapped the cable around the standoff between the ground plane for some stress relief. Also just filed down the lugs on a toggle switch we had on hand to fit the PCB holes for a power switch—no prob. In the end hardwiring the brick is probably better—since with a 10 year old—experimentation is a thing. She was definitely into seeing what, and at what rate, things might burn that got touched with the iron within reach. Haha. Bemused by the fact that nothing would hurt the silicone work matt.

She's going to pair this with dual ACAs (one of which she helped me build a ways back) and some speakers that we are building next—gift kit from a friend!

Tested it into M2X. Sounds fantastic—definitely gets PLENTY loud. Dead quiet to boot into 97db speaks—rendered the SP-10MKII beautifully. SO AWESOME!!!!!!!

Thanks of course to Nelson and his insane generosity.

attachment.php
 

Attachments

  • ACP+_0023@1500px.jpg
    ACP+_0023@1500px.jpg
    129.5 KB · Views: 1,815
  • ACP+_0014@1500px.jpg
    ACP+_0014@1500px.jpg
    340.3 KB · Views: 834
  • Poet-ACP_01.jpg
    Poet-ACP_01.jpg
    379.1 KB · Views: 815
  • Poet-ACP_02.jpg
    Poet-ACP_02.jpg
    385.2 KB · Views: 703
  • Poet-ACP_03.jpg
    Poet-ACP_03.jpg
    441.8 KB · Views: 373
  • Poet-ACP_04.jpg
    Poet-ACP_04.jpg
    478.7 KB · Views: 361
  • Poet-ACP_05.jpg
    Poet-ACP_05.jpg
    385.1 KB · Views: 350
  • Poet-ACP_06.jpg
    Poet-ACP_06.jpg
    394.6 KB · Views: 343
  • Poet-ACP_07.jpg
    Poet-ACP_07.jpg
    467.1 KB · Views: 378
  • Poet-ACP_08.jpg
    Poet-ACP_08.jpg
    333 KB · Views: 447
  • Like
Reactions: 1 users