A guide to building the Pass F4 amplifier

7.5mm spacing should be fine, though the recommended Elna caps are in stock.

I used the AS-5218 in my build as the 400va was out of stock. Only issue i ran into was lack of physical space for the toroid and psu board with rectifiers inside the 4U case, hence i had to stack them.

Heatsinks i used, also cheaper :p 531202B02500G Aavid Thermalloy | Mouser

mcandmar, how high were the spacers you used to mount the PSU board...I've gone and grabbed the 5218 as well... Looks like 3" might just clear... and give me enough room for everything else involved in that area. Can you confirm?
 
mcandmar, how high were the spacers you used to mount the PSU board...I've gone and grabbed the 5218 as well... Looks like 3" might just clear... and give me enough room for everything else involved in that area. Can you confirm?

Good guess, two 40mm standoffs ontop of each other ;)
 

Attachments

  • IMG_9136.JPG
    IMG_9136.JPG
    785.3 KB · Views: 466
Mcandmar, I am sneaking up on my F4 build. Questions regarding space in the chassis. I am using the Store's power supply boards, like your build and the Antek 5218 transformer. I would also like to include the softstart board and speaker turn on delay. Will the Deluxe 4U chassis be big enough or should I just go for the Deluxe 5U?

Thank you for your thoughts.
David
 

6L6

Moderator
Joined 2010
Paid Member
Mcandmar, I am sneaking up on my F4 build. Questions regarding space in the chassis. I am using the Store's power supply boards, like your build and the Antek 5218 transformer. I would also like to include the softstart board and speaker turn on delay. Will the Deluxe 4U chassis be big enough or should I just go for the Deluxe 5U?

A 500VA Antek, with the Softstart and Speaker protection? A 4U is going to get really tight. It may be possible, but it's going to be a Tetris game for sure. At the minumum you should not use the diodes on the PSU and instead just use bridges, and you'll need to mount the PSU board on the font panel as shown -
(no, this isn't the tightest use of space, but you get the idea...)


IMG_2385.jpg

Yes, the current PSU board and the current Deluxe chassis have holes and threads to mount it as shown, with the diode board removed.

How flexible is the value of the 3300pF line level ceramic disc cap? I'm not sure about that item. I swear I remember seeing Mr. Pass saying 22pF or 33pF now that I'm looking at that value...

It's not so much the value, but that it must be X1/X2 rated for use across the AC line. 2200-4700pF is fine. It's job is to suppress arcing and sparks at the power switch.
 
Mcandmar, I am sneaking up on my F4 build. Questions regarding space in the chassis. I am using the Store's power supply boards, like your build and the Antek 5218 transformer. I would also like to include the softstart board and speaker turn on delay. Will the Deluxe 4U chassis be big enough or should I just go for the Deluxe 5U?

Thank you for your thoughts.
David

4U is fine if you utilize the back panel area, i mounted the speaker protect there and the soft start next to the transformer. Note my soft start board is larger then the DIYAudio version too.

Some pics to give you some ideas...
 

Attachments

  • IMG_9320.JPG
    IMG_9320.JPG
    619.7 KB · Views: 641
  • IMG_9325.JPG
    IMG_9325.JPG
    864.1 KB · Views: 633
  • IMG_9290.JPG
    IMG_9290.JPG
    753.5 KB · Views: 611
  • IMG_9338.JPG
    IMG_9338.JPG
    777.1 KB · Views: 590
  • IMG_9295.JPG
    IMG_9295.JPG
    774.1 KB · Views: 339
Its not the only way, i have seen people mount the power supply board vertical against the front or rear panels, or you could separate the rectifier section from the power supply board and mount them separately, or use diode bridge blocks as 6L6 mentioned above. This layout just made the most sense to me.