25 Volts is not as efficient as 70 Volts. If you're running 70 Volts and the Amp is bigger than 100 Watts it MAY say on the back by the wiring terminals "Class 1 Wiring required". If it does then you should be running conduit or armor for the speaker wire and the amp and speakers should be in a registered enclosure etc. (In other words treat them as if they were 120Volt electrical appliances!)

If the amp says "Class 2 wiring acceptable" then no conduit is required. 25 Volt was created to handle those situations, since it is NEVER Class 1 wiring.

I haven't seen much 25 Volt stuff in the last 20 years.

European PA is usually either 100 Volts or 200 Volts (sometimes 50). Here in NYC we occasionally get a European company who'se opened an office and has spec'ed European PA equipment. We install it, but treat it as Class 1 wiring.

The long and the short is: Run 70 Volts wherever possible.


Sam

"Where are we going and why are we in this hand basket?"