Thank you for the information. From what I understood from your response, it is not good practice to combine in the same conduit communication cables with power wiring. That is information that I have heard with regards to standard 120V and higher voltage AC, but did not know if the 70V DC PA wiring was considered a high enough voltage or current to be a problem (for example power over Ethernet uses a higher voltage and current but is typically not considered a problem and is run within the same cable).
I believe that separating the PA wires from comm wires is good advice, but unfortunately good advice is not always good enough for some people. The client I am working for does not want to pay to have separate conduits unless required by an applicable code or standard. The ANSI/TIA/EIA-569-A standard states: "Co-installation of telecommunications cable and power cable is governed by applicable electrical code for safety." The applicable electrical code for safety in this case is the NEC and whether or not the PA cable is considered a power cable in the NEC seems to be based on what class of power source the circuit is powered by. This brings me to my original question: When outputting at 70V, is the CTs-1200 amp considered a class 1, class 2, or class 3 power source? In the CTs 2-Channel power amplifier user's guide it says that CTs amps require Class 2 wiring and on the photo of the amp in the guide it says "Class 2 wiring outputs" above the screw terminals (page 14). I just want to verify that it is still rated as Class 2 even when outputting at 70 volts. Is this correct? Thank you for your help.