How to use signal Example on Max 7?

Hi,

I'm working on the Signal example in Max 7. As it is, the gain gets set with the "set gain" but the signal is not actually connected to the pyext. So, I connect it, but then when I connect the output from the pyext to, say, the speaker, there is no sound. 

How exactly am I supposed to get signals into the pyext objects? They are working otherwise.

Thanks