I'm designing a system for shattering wine glasses with high intensity
sound, but my design doesn't "feel" right to me, and I need somebody to
tell me if I've forgotten something important. I need an oscilloscope to
measure the resonant frequency of the glass and a frequency generator to
produce it. I need stereo speakers and a stereo amplifier powerful enough
to generate the sound to break the glass.

But how do I correctly get the signal from the frequency generator into the
stereo amplifier. Do I need a pre-amp, or do I just wire it straight in?
If I need a pre-amp, how do I spec it, on the outputs of the freq generator
and the input of the amplifier? What if I'm using a receiver with the pre-
amplifier and the amplifier built-in? Can I just use the pre-amp that was
intended for the turntable?