Various microphone inputs in the building are fed into an amplifier, and from there, distributed to a patch panel that feeds various speakers. To my uneducated surprise, there is no jack on any of the amps allowing me to record. The output going to the speakers should obviously not be fed directly into a microphone input (on a smart phone, for example). What do I use to step it down? I assume there is a commercial product for this. How am I assured that the step down is at the right level.