Driving earphones with LM324 Opamp?

[Stutzer]

Hi there,
I intended to design a litte, simple audio mixer based on a
voltage-adder realised with LM324.
Unfortunately I don't hear anything coming out of the output yet.
So my question is: How do I have to design the "output part"?

Shoud it be ok to just connect the earphones in series with a small
resistor (eg 30 Ohms) between the output of a LM324 and ground?
(I drive the LM324 in dual supply mode with +5/-5 Volt..but I think this
should work, shouldn't it?)

Please help me out..
Thanks
D. Stutzer

 

[Externet]

Hi.
What impedance headphones ?