The Wire LPUHP 16W Power Amp parts GB

[qusp]

what size will the taps be?

just for instance running the mill through the other direction as well to give a grid-like pattern would dramatically increase the surface area/dissipation and i presume wouldnt take too much extra time to design, however machine time (which = money) would be almost doubled i guess

[hochopeper]

I'm speaking now before putting much thought into it ... but is there much likelihood that a bunch of us will be putting these in similar enclosures?

For mine I was intending to go for a monoblock style and mount each in its own enclosure close to the speaker.

Would there be much saving in buying enclosures in a GB?

The main part that I've not worked out is how much ventilation will be needed to allow heatsinks to work effectively.

Happy to be told its not worth it and everyone sort out their own though!

[Ed LaFontaine]

Interested in everything except hookup wire.

Actually, I'm glad qusp called it out in the OP. Apex Jr. has

PTFE Silver Plated Stranded Copper Wire, High temp, mil-spec

for $0.26 per foot. That is 16 ga. ... in 9 colors...

[HYPERTUNE]

qusp:

The fins are a touch over 3mm thick and 25mm high. , The gap in between is 6mm, which allows me to use a 6mm end mill that will be quite happy doing a 25mm deep slot. A smaller diameter cutter is much more susceptible to vibration and the feedrate and depth of cut has to be reduced accordingly. If I were to machine 6mm slots in the other direction also, it wouldn't leave much fin left and would probably reduce the total fin area. It also would make the fins very fragile which makes machining more difficult (read slower ) You are correct that we aren't restricted by your typical extrusion profile though. I could make the fins a wave shape for example.

Regarding a chassis, I did have a bit of a crazy idea of machining aluminium blocks to replace the heatsinks on the regs and buffers. These blocks would then be screwed to a finned billet chassis. This is probably overkill but maybe an amp with this level of performance deserves a nice thick walled custom chassis? It's small enough that a billet chassis would not be too out of the question cost wise I think.

I'll draw something up on Monday and post a pic in the main thread.


Edit : qusp, it's no problem to get other colours done, but my anodiser charges $50 minimum. So basically for $50 you could get 1 done or probably 20.

[opc]

Great thread guys!!! There is some very cool stuff here, and this is a great opportunity to make something much better as a group than any one of us could do by ourselves!

Hypertune:

I'll send you detailed info on the dimensions of the power amp where the buffers are. As a few people here mentioned, we will definitely need to use thermal pads on the junction to the PCB and the tops of the buffers. That should give us enough wiggle room to accomodate imperfect soldering and all the other tolerances. There are thermal pads out there that are every bit as effective (and sometimes more effective) than thermal paste, and this is even more true when the mechanical stackup is such that you cannot get perfect contact.

Also, count me in for 6 pieces:

Custom CNC Alloy Heatsinks, kindly machined by Hypertune

qusp 4
hochopeper 2
opc 6
_______
total 12

If you do have plans for a chassis, I might also be interested in that depending on price and whether or not you're willing to put that much work into machining parts!

If you did go that way, it really opens up a lot of options in terms of heatsinking.

Cheers,
Owen

[bcg27]

I'm interested in 2 heatsinks for sure. Potentially chassis as well depending on configuration and cost.

Custom CNC Alloy Heatsinks, kindly machined by Hypertune

qusp 4
hochopeper 2
opc 6
bcg27 2
_______
total 14

[1543]

I am also interested in 2 custom heatsinks, also interested to buy proper chassis. Thx for your great support of this project.

Custom CNC Alloy Heatsinks, kindly machined by Hypertune

qusp 4
hochopeper 2
opc 6
bcg27 2
1543 2
_______
total 16

[qusp]

aaaaaaaarrrrggghhhh i just replied to all of the posts directed at me and the forum logged me out while i was doing it so it all vanished, anyone else been having this problem the last few days? i spent bloody ages on it too!!

methinks there are a few bugs that have come along with the latest improvements.

anyway some might have noticed the first post has been updated; thanks to the mods, suggested by Andrew T and implemented by Jason; as of this morning the threadstarter now has full and permanent edit capability on the first post, so i'll be updating it periodically. i'll try and keep on top of developments, but if anyone sees any omissions or has suggestions for other lists or info that could be included please do.

this feature will hopefully help to ease the frustration that comes with repeating the same info, but we still need to get people to actually READ the first post.

i'll reply to people shortly, i cant do it again right now. i had gotten into the habit of copying a long post before sending just in case this happened, but it hasnt happened to me in a while so i guess i got slack.

[tommy thong]

I am also interested in 2 custom heatsinks Thanks

Custom CNC Alloy Heatsinks, kindly machined by Hypertune

qusp 4
hochopeper 2
opc 6
bcg27 2
1543 2
tommythong 2
_______
total 18

[hochopeper]

tommy are you just speculatively grabbing these now on the chance opc will do a run of extra pcb in the future without any changes to the layout?

@qusp, is it worth getting a list of who's in for pcb from opc and putting that in the first post?

I'd like to know the general opinion on how restricted the scope of the GB should be? For LPUHP specific items like custom machined heatsinks/enclosures there really isn't much point anyone but those who've got pcbs on the way getting any. Its a unnecessary drain on the time/resources of the volunteers.