Pictures of your diy Pass amplifier

Member
Joined 2004
Paid Member
SIT Amp

Looks like the tall vertical heat-sink is trending :)

I have my cover finished for the front of the amp. It's purely cosmetic.
 

Attachments

  • 20141002_180604.jpg
    20141002_180604.jpg
    75.6 KB · Views: 1,723
  • 20141002_180629.jpg
    20141002_180629.jpg
    344.9 KB · Views: 1,698
  • 20141002_180717.jpg
    20141002_180717.jpg
    423.3 KB · Views: 1,660
Looks like the tall vertical heat-sink is trending :

Too tempting and unique to resist :rolleyes:. Got saws and drills sharpened for a version of the heatsink concept - hopefully to house a BA-2/3 (prelim sketch indicates ~ 16" tall X 8" dia.). Don't really need/want the computer but kudos to Apple (New Mac Pro) for pushing the envelope again. Should be a fun winter project to apply to the amp chassis world :D.

(@ Admin - Hopefully no copywrite violations with photos here :))
 

Attachments

  • Capture3.JPG
    Capture3.JPG
    53.9 KB · Views: 1,681
  • Capture.JPG
    Capture.JPG
    37.4 KB · Views: 1,688
  • Capture2.JPG
    Capture2.JPG
    18.6 KB · Views: 1,749
  • Skth.jpg
    Skth.jpg
    33.9 KB · Views: 1,650
Hi, many thanks to Mr Pass and the diyaudio community here :)

Here are some photos my little ACA build. It's still a bit rough around the edges, but if I wait to finish I'll never post photos. I have sandwiched the MOSFETs between a PC CPU heatsink and a small 40x40mm heatsink. The MOSFETs all sit nicely within the foot print of the heatsinks, with a few mm of space between them.

I used a Cooler Master PC CPU heatsink (this one), which I picked up dirt cheap on ebay (~£10GBP). It's quite nice because it has metal feet with holes, so I was able to screw it down through the box. I've tried some other CPU heatsinks, but this one has been the best so far.

I removed the big fan from the CPU heatsink, it happily radiates passively. The 40x40mm heatsink is using a small fan, as the black side of the MOSFETs does seem to get warm otherwise. The small fan is supplied through a small DCDC switch mode step down (ebay again, ~£3GBP), just visible as a blue PCB in one of the images. That small fan is running at 5v (rated for 12v), so it is not audible. As for signal noise... the amp runs from a switch mode supply anyway, but I'm not sure! I'm delighted with how the amp sounds in any case.

In use the PC CPU measures at 50*C max. Without the small fan active the that rises to 70*C. So it is possible to run it passively and hot :)

I'm driving a pair of Fostex 206EN in transmission line enclosures. I've been using this amp for 5 months now :)

Thanks again!
 

Attachments

  • 5 - QTURHVt.jpg
    5 - QTURHVt.jpg
    953.1 KB · Views: 619
  • 4 - 7bv8u4N.jpg
    4 - 7bv8u4N.jpg
    958.7 KB · Views: 833
  • 3 - K60hiu7.jpg
    3 - K60hiu7.jpg
    933 KB · Views: 834
  • 2 - MNLVJwI.jpg
    2 - MNLVJwI.jpg
    486.7 KB · Views: 783
  • 1 - FshmGMm.jpg
    1 - FshmGMm.jpg
    482.3 KB · Views: 1,614
I've been building this thing from scratch, it's supposed to be a F5 with doubled output stage and 32V rails (turbo v1).

My woodworking skills are very bad, I'm already happy that the whole thing doesn't collapse. No tools whatsoever. A drill, some drill bits and a file. I really wish I had screw terminals.

Front board not ready yet.

Photo-skills bad as well, sorry :)

However, happy listening to it. Been a long ride and I've learned a lot - and there's probably a lot more to learn :)

Thanks to all who encouraged me building this thing.
 

Attachments

  • top.jpg
    top.jpg
    431.9 KB · Views: 753
  • front.jpg
    front.jpg
    335.4 KB · Views: 764
  • back.jpg
    back.jpg
    374.1 KB · Views: 530
  • side.jpg
    side.jpg
    430.6 KB · Views: 555
nebiki, you should at least cut large holes in the sides directly opposite the coolers to the hot air is ejected out of the cabinet. You can do this with a $10 coping saw by drilling four holes at the corners and cutting from hole to hole with the coping saw. You can attach screen outside the holes to prevent intrusion.

Tell yourself this: it's a first try. You can remount the amp later in a better enclosure if you desire as your skills will increase :)
 
Okay, since this enclosure is a "test" only, I decided I would do what you said, just a little bit different.

I've drilled a few 10mm holes on the sides where the coolers sit.

It helped a lot. Right now I have only one side drilled and the temperature difference between the channels is above 10°C.

Thank you :)