ApexJr AlephX?

[tiroth]

I've been eyeing those tunnel heatsinks ever since Steve put them on his site. Now I've finally done something with them.

This is using four of those sinks per chassis. It will probably be a couple of months before these are running due to other distractions, but I thought I'd post some thermal and electrical measurements given the recent round of AlephX orders.

[tiroth]

This is a pretty low-budget solution for an AX chassis and PSU. I am using the Signal BL 1752, 12-0-12 @ 7A and costing only $8! I followed this with a C-R-C-R-C supply, using those 68,000uF 50V caps and 25m resistors.

This supply delivers 13.3VDC at 3.3A with 13mV of ripple. The transformer is cold after running for 1 hour.

[roddyama]

Originally posted by tiroth
I've been eyeing those tunnel heatsinks ever since Steve put them on his site. Now I've finally done something with them.

I think we all look at heatsinks like a dog at a porterhouse. It's unnatural I tell you.

Originally posted by tiroth
This is using four of those sinks per chassis. It will probably be a couple of months before these are running due to other distractions, but I thought I'd post some thermal and electrical measurements given the recent round of AlephX orders.

That looks as if it will turn out pretty nice. How much power? Ah, I see now. Scratch the power question.

[tiroth]

Now the fun part: thermal data. Each side (2 of the tunnel sinks) is good for about 0.44K/W at a 35K rise from ambient.

All told, it is hardly frugilephile, but I think this has to be one of the cheapest ways to build a 30W AlephX. If you are willing to run it hot, and spend more than eight bucks on the transformer, you can probably squeeze ~100W of output out of this chassis/supply. I wanted it to be upgradable.

For anyone interested in copying the design, I used .25"x8" aluminum plate for the panels. The front and rear are outset because that plate was shear-cut and tolerance was off by nearly 0.5"! I recommend using 8" bar stock for this reason. Lowcostmetals.com is a decent source, just bear in mind my experience with their tolerances.

BTW, the title of this post is due to the heatsinks, caps, and transformers all coming from ApexJr. I am not affiliated with them in any way.

[tiroth]

Thanks Rodd. It gets interesting when postings get interleaved like that.

[JohnSz]

Hey, I've eyed those same heatsinks at ApexJr Maybe on my next order. On my last order, I picked-up a bunch of his Nichicon 10000mfd 80V caps. Just starting to put them to use in an amp mod

BTW, I have placed a number of orders with Steve, over the last few years. Always satisfied.