ACA Redux

Hi N Brock,

Very nice work and amazing thinking to get us away from making a chassis or having to solder any wires. Bravo! :cheers:

LED cooling is the new CPU cooling. If we look around we can find an easy to use rectangular format 160mm x 68mm x 40mmH heatsink that has predrilled tapped holes and even two copper core heat spreaders and built in fans. Replace the noisy fans with Noctuas and you have something that can easily run with higher power amps dissipating 100w+ per channel. This one is $30 with shipping. The existing tapped holes can be used to clamp a plate or bar that would press the MOSFET body right over the middle of the copper core. No need to use one screw on the MOSFET. Underhung flat mounted MOSFETs can be easily clamped this way using PCB as the clamp. Maybe 2mm thick FRP for more stiffness. A desktop M2 or F6 could probably be realized this way.

When we look for heatsinks for high power “COB matrix LEDs” the world of affordable heatsinks really opens up. LED heatsinks commodity items that are extruded by the miles I am sure, hence the cost is very low.

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Hmm... how tall would an F5 v3 Turbo or A2 be using such vertical heatsinks? Would it take a single 20 inch tall Tower Of Power per channel or perhaps several shorter Towers?

They'd be like mini Pipe-o's -with amps like that, my wife might warm up to the idea of a pair of eight foot Pipe-o's in the living room. I mean, she's used to the Maggies already.

Anyhow, back to the vertical heatsinks for the higher powered amps... maybe add a row of them, standing up, next to each other instead of those "boring" standard heat sinks we're so used to. it would make an awesome looking A2.

In the meantime... will this become a kit we can buy? It's really nice, thanks for the great work!

Mark Johnson

Paid Member
2011-05-27 3:27 pm
Silicon Valley
I really like this project, and because imitation is the sincerest form of flattery, I copied it :)

I added two upward facing pink LEDs (Mouser P/N 604-WP7113VRVC1C) to illuminate the black pin fins, and also a "breathing" blue LED (sold HERE) for the On/Off pilot light.

I added a "PO89ZB" power supply filter circuit (LINK) on the round PCB, to remove switching power supply noise. The filter components are in the top right corner of the board, at 2 o'clock.

Finally, I got rid of the expensive 2SK170 / LSK170, and replaced it with a Fairchild J112 which costs less than $0.65.

A huge thank-you to Nelson Brock for inventing and unveiling this project! I hope he decides to make it available to diyAudio members in some way, possibly bare boards, or partial kits, or full kits, or downloadable Gerber files. He deserves to be economically rewarded for his hard work.

However, if he decides not to, and if he gives his permission, I'll make this "RACAM" available to members. Probably in a new thread.

Mark Johnson
(8 attachments below, schematic is the last one)


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