The reason that jack doesn't work for a microphone is because it's a headphone jack. It's meant to send a signal out to headphones, and it doesn't work as an input. If the receiver doesn't have a microphone input jack (and it would be clearly labeled as such), you'll need to connect your mike through the auxiliary input. You may be able to connect with nothing more than an adapter to switch from the plug on the end of the mike cable to the RCA jacks on your receiver. The output level on some mikes may be high enough to drive the auxiliary input as-is. More likely, though, the mike will need a little boost to make it work with the receiver. The receiver needs a "line-level" input, which is higher than the output of most good-quality mikes. To get the mike up to line level you'll need a microphone preamp. There are many types from many sources, at a wide range of prices. Here's one
I have used as an example.
You might also want to look for a small mixer like this
. The mixer would let you combine your mike and music source into a single line-level output you could run to the receiver, and use the receiver just for the amplifier function.