I'm not too astute on daisy chaining amps or working two amps in combination... so I need a little help or clarity on how this works. Is the Preamp Out jack used to daisy chain another amp and controlling the preamp section of the other amp? Are the controls interactive on both amps or just the one that's chained to the second? Is the Power Amp In jack used to connect the preamp of another amp to the HRD? For example if I used my Pro Junior and connected it to the Power Amp In Jack, will my Pro's preamp now/solely be running through the HRD? thanks for any input.