Why is there foam tape on my amps heat sink

My guess(tm) is that it's to reduce or prevent vibration of the heat sink in shipping. It's difficult to tell from your photo, but it looks like the heat sink is only supported on the PCB end, with the upper end floating free. Such a construction could cause the heatsink to vibrate in shipping, and eventually break something on the PCB end.

If someone sat on the amp would the heatsink touch the casing?

Yes, depending on who will be sitting on the amp: I don't think a little foam tape is going to help.

If there was a fan, I could see it's use to block free flow.

Greg

Thanks for your reply.

I know it is hard to see from the pic but the tape is not on the top face of the HS, it is actually on the HS fins with the edge of the tape pointing up and down. ie the sticky part of the tape is on the fins

Please see my post to Jeff. You are misinterpreting the pic (know is a lousy picture). Actually picture 2 shows a better close up (

Greg, There is a fan.

If you look at the first picture, there is a black hood to the right of my text. Under the hood is a fan. It doesn't look like the fan actually blows into the heat sink as the other side of the fan appear closed (unless the holes are on the bottom face, which I cant see).

Do you think I should try to replace the tape with something? what?

Should not get too hot. Some more weather-stripping or pipe insulation.

Greg

It's difficult to determine if the tape was jammed in between the heat sink and the top cover from the photos. If it was, it might be a transport vibration damper. If not, as you describe here, then perhaps the tape was improperly installed at the factory?

Drivel: I once owned a 1970 Land Rover Series 2A. A feature of the engine was a length of sheet metal between the spark plugs and the firewall. As far as I could determine, it served no useful purpose and was perpetually in the way of doing normal engine maintenance. One day, I decided to remove it. Nothing happened until I hit about 50 mph on the freeway, when I heard a loud low pitched whine coming from under the hood. The wind had turned the engine compartment into a giant whistle. Beware of such non-obvious design features when removing tape, gum, goo, and other obvious band-aids.

Think about the casing flexing down just a bit. Possibly when you place another component on top of this one. Add some vibration and the heat sink will buzz against the case. This is probably what the foam is for.

You know I am just going to throw this out there, could be it or could just be a blow of smoke but....

What if maybe the heatsink fins exhibited a resonance at some audible frequency ? I mean like they found that under certain conditions the loud audio would excite the them to vibrating at say 6 Khz ?

Stranger shit has happened. Remember I'm the guy who had to adjust the vertical height to keep a TV from turning all red. I shit you not. For the puzzled : It had to do with AKB. Details on request.

(Never attribute to design that which can best be explained by sloppy assembly).

Maybe the foam tape is there to protect the heat sinks during production and someone forgot to remove the tape? Or, it could be there to protect the workers from the sharp edges? Or, maybe someone just installed the tape in the wrong location?

Drivel: One of the radios I worked on had a crystal oven that was thermally insulated with some styrofoam. At least once a month, we would receive a radio back for repair, with the styrofoam removed. When asked, the customer or dealer would usually mumble something about the styrofoam being packing material.

assembly)"

Thou hast coined another Leibermannism. What number is this one ? :-)

X.XXVI.MMXIII

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