Hi,
Here are some pics of the finished HTPC. Sigma11 power, Onkyo SE-200PCI sound card with LME49720HA op amps and Blackgate NX coupling caps. I'm using a remote but I'd like a small screen - what did you decide to get Punnisher ?
The Sigma11 uses three FC 4700uF 25V caps to reduce pre-reg ripple, which could get quite high under a heavy load. It also uses five 2.4 deg/W heatsinks. The mosfets are running at 37.2 degrees so there's plenty of 'extra' for more current/heat. I didn't use electrical pads for the mosfets cos they add 3.3 deg/W so I've isolated the whole Sigma11 from the PC. There's plenty of space around it. The toroid in the top also has clearance to avoid a shorted turn. The toroid is 0-15V 50Va, so that's 3.4A max and a safe limit of 80% is just under 3 amps.
With a notebook hdd the peak current demand (during boot) was 1.8A. This included a usb notebook dvd , wifi, 2gb memory, Onkyo, keyboard, mouse, vga 1920x1200. It is about 1.3 amps steady state now because I'm using the ssd and no dvd. I left a space and SATA cables to add a 3.5" HDD in the bottom, which I'll get when 2Tb drives become more affordable. Rubber/wood/foam mounted of course....
I got the heatsinks from a local shop but they are available here :
http://hongkong01.rs-online.com/web/...uct&R=490-7135
I bolted all five together with heatsink compound and cut the front one up a lot to mate it with the mosfets, board, caps etc.
The PC case is only slightly warm at the top and cold at the bottom so the case is well ventilated enough.
There's a bit of copper board to screen the sound card from the mobo.
Noise on the 12v line on the mobo/ssd shows there are dc converters at work. My dmm says 1.5mV AC but a scope shows a broadband of fuzz that is about 4mV wide and there are noise spikes up to 20mV. Although this is a shame, it is much better that what I got running from an smps psu. 'm content for now, but sometime in the future I'll see what sort of noise there is on the sound card caps and see if I can knock that down a little too. I'll also add a resistor to the front led - it's way too bright.
BTW, it sounds great !