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DIY PASS F5 BUILD THREAD

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  • Replies 110
  • Views 36.7k
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  • Author
Why are the lower right and upper left capacitors not connected to +?

No idea, I'm assuming they'll be connected somewhere at some point.

Marc?

Why are the lower right and upper left capacitors not connected to +?

Because they are the output of the CRC filters. So, the "D" goes to +V on each board and "A" goes to -V on each board and then GND goes to GND on each board. I'll double check things, but that should be correct.

Steve, are you sure you don't have those other resistors? :palm: Can you check the invoice?

  • Author
Because they are the output of the CRC filters. So, the "D" goes to +V on each board and "A" goes to -V on each board and then GND goes to GND on each board. I'll double check things, but that should be correct.

Steve, are you sure you don't have those other resistors? :palm: Can you check the invoice?

Oh, were they supposed to arrive with the 1K resistors that just came?

The invoice is long gone, but I'm positive they weren't in that shipment, just 6 of the 1K resistors.

Oh, were they supposed to arrive with the 1K resistors that just came?

no, the one you ordered (you may have an invoice in your e-mail). let me see what I have. I know I have some, just I have no idea how many..

  • Author
no, the one you ordered (you may have an invoice in your e-mail). let me see what I have. I know I have some, just I have no idea how many..

I clean my email inbox regularly, so no luck there. It's no problem to order them though, I'm not going to be finishing the amp in the next week or so for sure.

  • Author

Well things are progressing nicely. I've got most of the parts wired and milled. I still have some wiring to do to the boards, and I need to put the case together after that, but that's easy enough.

Next up is to mill and glue up the wooden faceplate.

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This thread makes me want to build a F5 too. Looks awesome so far!

  • Author

Thanks, it's fun, and it's giving me some confidence for the next project.

That's basically what I'm hoping to achieve with my bookshelf project, gain some confidence with woodworking.

  • Author

Well I'd say you should already have quite a bit. You have the attention to detail that's needed. Everything else is just familiarity and tricks of the trade, both of which come with time.

looks good Steve!

A few notes:

measure the resistance between the binding posts and the chassis. This should be an open circuit, or infinite resistance. Measure the same between the RCA and chassis. These should have come with shoulder washers to make sure the post won't contact the hole... now's a good time to verify this.

Those black discs (thermistors) in the PSU will get warm. I'd recommend heat shrinking the leads and trimming them down so they don't accidentally get knocked around. Important thing is that nothing touches the leads and the don't really touch anything and are relatively secure so they won't move around. For example, you could bend the one on the rear panel at a 90 degree angle to get it away from the aluminum case. Same thing with the little thermistors on the amp boards. Also, you'll want to sort of bend the leads of these devices down so the black head is sort of near the mosfets. Think of these like little thermometer probes that need to sense the temperature of the mosfets.

The rest of the wiring is sorta simple. You need to run wires from the +V on each boards to the caps (upper left I think?) and -V on each board to the other output (lower right?) and GND to the copper. Also, you need to connect the inputs and outputs to the rear panels. I'll leave this as an exercise to the reader :) Leave lots of slack in the wiring to facilitate tearing things down if need be.

Fantastic work in so little time!

does anyone know where i can buy heatsinks used in this amp build?

Mark

does anyone know where i can buy heatsinks used in this amp build?

Mark

sure, if you're willing to by a ton of extrusion. They are made by R-Theta.

I see. It was tough telling how tall they were without a frame of reference

Just curious, did you pick up those 12" wide heatsinks through a group buy?

  • Author

I think the ones I got were from someone who backed out on a build, but I really can't remember. Marc set it all up for me.

  • 2 weeks later...

I'm going to be wiring up my (finally here and the worse for being packed by a moron) F5, but (one of the) doubts that occurs to me is what sort of wire I might need to use. I've got lengths of generic speaker cable, CAT5 and such, but it occurs that I might be supposed to use a particular spec wire I don't actually have in case it melts or something.

Advice?

  • Author
I'm going to be wiring up my (finally here and the worse for being packed by a moron) F5, but (one of the) doubts that occurs to me is what sort of wire I might need to use. I've got lengths of generic speaker cable, CAT5 and such, but it occurs that I might be supposed to use a particular spec wire I don't actually have in case it melts or something.

Advice?

Probably stranded copper wire, but I'll let a more experienced builder chime in.

For all the AC wiring you should use 300v rated wire but since the rest is all low voltage stuff you can use pretty much any wire you like, given that it can handle the current. 16-18AWG is plenty for anything this amp can dish out and 20AWG could even be enough. For the input wiring you can even use 30AWG or smaller but stick with 22-24AWG since they are easier to work with. As for the insulation, teflon has the extra benefit of not melting and thus not potentially contaminating the solder joints.

  • 2 weeks later...
  • Author

Well this weekend brought the F5 very close to being complete. Luvdunhill, Pabbi1 and myself had a DIYfest at Marc's place, where the boards were wired up and the amp was powered up for the first time. Unfortunately the amp kept blowing fuses immediately upon fire up. Marc is hosting the amp for further trouble shooting, and may already have the problem figured out.

Shouldn't be too long for some initial impressions.

For pics please refer to the Austin meet impressions thread...

http://www.head-case.org/forums/meet-impressions/6219-diy-mini-meet-austin.html

  • 2 years later...
  • Author

Dredging up one of my old threads to reveal a happy ending.

Marc and I (Marc) were unable to get the F5 to play in any kind of stable manner back in May of 2009. Well Marc wanted some help with his new corner horn project this past weekend, and kind of as a way to entice me up there I guess, he broke the news that the F5 was alive and in top form.

It seems he spent a lot of time getting it to that point...new PCBs, major tweaks to the power supply and some resistors to play well with the K1000.

She looks and sounds fantastic! It's a little bit of a different flavor for the K1000, and a nice compliment to the β22. And it sounds amazing with my custom built speakers.

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