[Amps] Acoustic Noise Comparison

[Ron Youvan]

   Jim Barber wrote:

> I'd hate to warp the cover MIG welding, but then I'm no welder at all -
> just guessing.
> Also - just read your last... Angle stock would be stronger, but we're
> trying to dampen resonance. my seat-of-the-pant-ometer says flat bar
> would be perhaps just as effective and would have a flatter profile.

> I hate to admit this in public, but the last one I fiddled with I used
> 1/2" MDF in strips, first sealed with a 50% solution of yellow glue and
> water, then glued (press-clamp HARD) to the underside of the cover with
> Gorilla glue. I spent too much time "cutting and trying", but in the end
> it worked well and although I haven't heard that it's ever come off, it
> would be non-conductive if it did. I'm planning the same treatment for
> *my* QRO HF2500DX, which suffers from a cheap-but-easy-to-replace,
> solid-mounted Dayton blower and a huge sheet metal cover. That one's
> also getting an EBM-Papst ball-bearing unit with a cast housing,
> assuming I can make it fit.

   I have never worked with MDF, but I think it is a wood product (or a plastic product)
and an old rule for power amp construction is: never use a combustible material anywhere near the 
action.
I have seen silicone, fiber glass coated wire and fiber glass board made of what looked like dental 
cement, a sort of glue that was not flammable used to NOT support combustion.

-- 
    73 Ron KA4INM - All E-mail sent to this address shall linger in the Google cloud forever!