Pub. Address volume & wiring?

The taps are on the primary. you select the tap to give the required level at each speaker. the total should be close to the amplifier's rated output power, in watts. The wiring requirements depend on the voltage, and your local codes.

Assume you are talking about "70-volt" (or similar) wiring systems also known as "constant voltage".

Or differences in: room size, noise, desired levels, speaker efficiency, etc. etc. etc.

If they are "constant voltage" transformers, they will typically have serveral PRIMARY taps to adjust how much power/volume you feed to that particular speaker. If you are using "70v" transformers on a 70v line, the taps are typically labeled directly in "watts" (how convienent!)

SOME constant voltage transformers ALSO have SECONDARY TAPS. But most of them that I have ever seen are "hard-wired" for 8 ohms output/secondary. Typically labled "4 ohm", "8 ohm", "16 ohm" etc.

With the PRIMARY taps.

Depends on your local jurisdiction. I believe the National Electrical Code (widely used across the USA) allows 70v to use "class 2" wiring. 100v may have to use the same wiring as power circuits.

On Wed, 14 Jan 2004 20:28:05 -0800, Richard Crowley wrote (in article ):

Indeed, I've refreshed my memory and it says "70 volt" on the amp's output terminals.

I'll ask the local building inspectors about 70 volt audio wiring.

Thanks,

If I have an amplifier that doesn't have 70-volt output, can I use a constant-voltage transformer in reverse, putting the 8-ohm winding to the amp? Then I could connect the 70-volt winding to the wires to carry the current to the speaker where there would be a traditionally-connected c.v. transformer.

Accepting the absolute of loss in the transformers, this should work OK, shouldn't it?

Thanks,

How do you think they get a 70 volt output in the first place? They install the same transformer on the chassis to convert the low impedance to 70 volts. MCM carries three transformers for this: