Krell Industries Power Amplifiers MDA-300/500 Owner's Reference Manual page 7

Thepin assignment for the XLR is:
pin _1-= shiel-d (ground)
p!n 2 = non-inverting input (hot)
pin 3 = inverting input
NOTE: The RCA center conductor for each channel is
wired_in, parallel with pin 2, the non-inv, erted input. Only
one ot these inputs Should be connectecl to a preamplifier.
3. Insert the AC pow6r cord into the receptacle located on
the back of eachMDA-300/500. Insert tile other end into
the wall AC receptacle. (Refer to section C, Basic Instal-
lation and Operation, for AC power requirements)
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