Crown DC-300A Instruction Manual page 24

3.5 CLEANING
The CROWN DC-300A has a rugged anodized front panel
for life-time service. The panel can be cleaned with a
moist cloth and mild detergent. Never use steel wool,
scouring powder, lye solution, or any strong abrasive
cleaner as these will damage the panel's finish.
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The back chassis should require no more cleaning than
periodic dusting with a clean dry cloth. The use of de-
tergents, abrasives or other cleaners may remove the
fine film of oil from the black anodized chassis which
is used to increase its surface lustre.