aleph 2 progress

[Mark A. Gulbrandsen]

Brian,

Then yours may work more reliably, longer using the sinks I bought. Although the sinks are more work to incorporate into a chassis they sure are extremely efficient and I see why amp manufacturers used them in early Class A power amps. It may ahve been the largest stock sink that was available a few years back.

Mark

 

[Brian Donaldson]

Mark,
Your extrusion was very tempting. The small base with fins radiating off in all directions is the most efficent design, but I wanted something that would more easily fit into a more traditional sized rack. But you can't possible put 2 of the 75 pound heaters in a rack. They would melt the plastic buttons and face off of the SACD player.

Here's what I'm using for my ugly, noisey, attic mounted big *** Aleph X. I was told that it could disapate over 1 KW with forced air. It's 9" x 12" x 3"

 

[SI]

Mark, how about posting some pictures of your heat sinks

 

[Mark A. Gulbrandsen]

Ok, here ya go. These were brought on line Christmas Day, a year ago last Christmas. I've been so busy listening plus there has been a somewhat continous stream of locals that saw the post back when I got them running that have also been over so they remain un-anodized, and no front panel. This is going to change though in the near future as I am planning a serious PS upgrade to 1KVA toroids from my 680KVA units plus a CRCRC filter bank. So they will be torn down, things re-machined to accomodate the bigger tranny, and capacitor bank and relocate the driver board elsewhere plus a front panel and top cover....then over to the anodizer for hardcoating the black heatsinks and chassis parts and a hard coated pewter front plate. I prefer hard coating as its far more scratch resistant and not all that much more expensive then plain anodizing.

I literally built these on my kitchen table! I did all the machining on Saturdays and in the evening at work on our shop.

Mark

 

[Mark A. Gulbrandsen]

here is a layout shot fomr size comparison. The toroid is 680 va and thats Brian GT's pcb in the shot for size comparison. The statement these sinks makes is definately one of high power and heat !

Mark

 

[SI]

Awsome Heat sink

How about a link. I'm building my very first Aleph 2's, for that matter my first any thing, So I'm no expert on this, But shouldn't the tranny be as far from the I/O as possible. In other words would it be better if you were to swap places between the PCB and the Tranny in your layout.

Are you mounting the fets right on the heatsinks?
They are awsome.

SAAD//

 

[jewilson]

Mark,

I have a bunch of those types of heat sinks however I’ve never used them. I always though that the middle channel was meant for mounting some kind of Stud SCR, high-powered diode or transistors.

Since the channel is narrow, I just never used them. Therefore, I wonder how well they will work since you have only conducting heat through narrow flats of the fins. I though the part you are using was just meant for mounting to a chassis.

Let me know how they work out for you, maybe I'll use mine or dumb them.

 

[Mark A. Gulbrandsen]

Here's how I mounted my devices..... inside the shallow end of the channel. Those turret terminals are about 35 cents each and make things a bit more solid and are very convenient. If you need any let me know.

The outer banks terminated back to the center sink and then went to the driver board. This way all the output stage connecting wires were basically the same length.
Mark

 

[jewilson]

Mark,

Dumb me; I should have realized that you did not sink the sinks just to the chassis fins.

That looks good, that must have been a real hassle trying to get the parts in there. Those turrets are really worked out well, or they 4/40 or 8/32 threads.

Yea could use some.

 

[Coulomb]

Well if someone wants to organise a US Contingent to this Group Buy I am trying to get going, then I could arrange a drop ship from the vendor to one US location for reshipping.

The prices are excellent and the more I buy the better the price should get. Take a look at this thread for drawings and pricing. Remember the pricing is in Canadian dollars so for a rough conversion to US multiply times 0.7.

Sorry for the spam guys.

Anthony

http://www.diyaudio.com/forums/showthread.php?s=&threadid=29816

 

[tomchaoda]

My Aleph 2 preparation report

While I am waiting for my Aleph 2 PCBs and GP cases to arrive, I made my preparation in a journal type of report. I would like to share it with you and also pls feel free to comment the contents. I did the preparation based on my previous journal of Aleph 5.
Here's the link:

http://www.penguinlovers.net/audio/aleph2_proj.html

If you don't have a boardband net, e-mail me and I will e-mail you entire files in a zip.

Thanks,

Thomas