"Fabio Berutti" wrote in message
...
IMHO aluminum is too weak

Which is why you use thicker pieces. And as a matter of fact, 7075-T6 is as
strong as 1018 cold rolled (and 2.7 times stronger and stiffer by weight).

and bends and sticks to the tools.

They sell WD-40, y'know... it's not just for displacing water anymore! (No,
it never was, and never will be, a spray lubricant!)

Steel is too hard, particularly stainless...

They also sell this new wonder metal known as High Speed Steel.

a guy here in Milan made a 6550 PP amp out of a large
rectangular (reversed) oven pan, some 4-5 mm of AISI304. I suppose it's
...
well .. robust.

Nice.

I'd say that copper is the best of all in terms of ease of machining:

Gack choke sputter!!! Pure copper is about the gummiest thing you can find.
(They say razor sharp tooling and milk for cutting fluid is the best you can
do.) Copper alloys like brass and bronze generally machine well, but are
too "slippery" (hence their use in bearings) to cut with anything but the
sharpest tools.

just
remember to paint it with a protective transparent lacquer as soon as You
finish polishing it with sandpaper, or it will get brown in a wink.

Or green, or blue. Unless you want that. In which case, toss it in your
litterbox for a week.

A further advantage of a 3mm copper plate is that it IS definitely a
ground
reference, at least for a power amp.

Not that using the chassis for grounding (unless done very carefully) is
ever a good idea, of course. This I know from personal experience...

Tim

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