Heatsink

[davidlzimmer]

Going to build a parallel LM3886 stereo amp. What do you guys think of this heatsink cut in half?



Two LM3886s on each. Placed on top of enclosure with fins up. The power supply will be in separate enclosure. 33.5 V rails. 4 ohm load.

URL]cgi.ebay.com/RAW-HEATSINK-ALUMINUM-EXTRUSION-12-long-CUT-FREE_W0QQitemZ7622015198QQcategoryZ31489QQssPageNa meZWDVWQQrdZ1QQcmdZViewItem[/URL] this

[jleaman]

Originally posted by davidlzimmer
Going to build a parallel LM3886 stereo amp. What do you guys think of this heatsink cut in half?



Two LM3886s on each. Placed on top of enclosure with fins up. The power supply will be in separate enclosure. 33.5 V rails. 4 ohm load.

Just so you know this is where i get all my heat sink's too. Russ Is really good.

[dfdye]

HUGE overkill, but it will definitely work! I was looking at those myself the other day. Let us know how you like it if you decide to buy it.

[davidlzimmer]

Overkill I like!

[maurycy]

If you want to save some money, you can do what I did. Saturday morning to a garage sale in your area and pick up an old receiver. Last week I got Pioneer SX-650 for $10. I am going to use heatsink and knob(s) from it. Maybe sell the transformer on Ebay to get my $10 back.

It is tough to part such a nice piece of equipment though . I like the analog meters.

Alex

[N-Channel]

David,

Definitely Overkill, but it DOES look nice. Does he have any black anodized ones?

Steve

[davidlzimmer]

Yes he does. Check out his "other items"

[poobah]

Those prices are fair as well.

[davidlzimmer]

jleaman,

I'm hoping I can run the 4 LM3886s hard without the need of a fan. What has been your experience with these heatsinks?

Thanks,

[!]

You guys crack me up.

IF he actually needs paralleled chips (if it wasn't just a wasted 2nd chip), AND he cuts it in half so 6" x 5 3/8 x 1, AND it's placed on the top of the enclosure so convection is sub-optimal, and considering how dense and short the fins are so not as much cool air circulating through them,

it is not even close to overkill, might actually be marginal.

Some of you seem to think "my amp never gets very hot", but then you never actually push your amp, or run it at lower voltage, or any number of things that have an effect on dissipated heat. The truth is in the spec sheets and design guides. The goal is not merely to keep it under a meltdown temp, but WELL under that temp which also effects max output before the protection circuit kicks in, and may also effect the lifespan of the amp in decades.