ARC Reference 10 melting polycarbonate cover

Thanks for your answers. I decided to remove the cover and see what happens. Maybe, will make a couple of holes over the 6550's.

That sounds like the Wizard of Oz...damned Dorothy!

Losbears, you mention not hearing any difference between to poly or metal cover. Have you heard any improvement by not using any cover, or was the heat dissipation your motive? Just curious about my LS26.
Thank you

Theo, I can't hear any difference with the cover off. Though I have heard this theory for years. I tried this experiment years ago with my LS25 mk2 and could not hear any difference then either.

The problem with the Ref preamps is that the top of the 6550 tube is very close to the poly cover. This causes a slight upward circular bump in the cover. It still happens with proper ventilation. I have an open rack with about 5 inches above my Ref 5se.

That said, The Ref 5se is an incredible preamp. I can only image how much better the Ref 10 is.

I had the problem with my Ref2 SE phono stage. I thought I was going to have to buy a new rack as the one I have only has about 3" of space above the ARC and the next shelf. The poly cover was starting to bow above the 6550.

A cooling fan solved the problem. I think the fan is a good idea even if you remove the cover. Cooler operation equals longer life.