View Full Version : Altec 2280A mainframe amplifier question

07-04-2010, 10:45 PM
Hello, I have several questions about an Altec 2280A Amplifier. It is a mainframe that I have set up with the 8 amplifier modules paralleled into a 1 channel at 600+ watts @ 8 ohms.One of my Questions is since this is a 70 volt amplifier and I have it set up into 1 channel @ 8 ohms is it still 70 volt output? The reason I ask is when I measure the voltage on the speaker output connections it reads no voltage with the volume (on a connected preamp) set at zero and as I increase the volume the voltage on the output goes up. So if I have the volume at say 9 O'clock then the voltage is at about 10 volts or so and as I increase the volume the voltage increases. So I would have to set the volume at 12 O'clock to get 35 volts or so and all the way up to actually read 70 volts on my volt meter at the output.Is this the normal way a 70 volt amplifier works? Or is the output supposed to be 70 volts at all times? I know I am supposed to connect a step down transformer at the speaker end and it steps the voltage back down and makes it into 8 ohms for the speaker. But the manual for the amplifier says if all 8 of the amps are paralleled then it is 8 ohms, so do I need the step down transformer at the speaker when set up as parelleled? How much voltage does it take to damage an 8 ohm speaker? Like if I didn't use a step down transformer and just connected directly to the speaker and never cranked the volume over 9 o'clock or so then only 10 volts or less would reach the speaker. Is that enough voltage to damage a speaker? I'm wondering because I heard a step down transformer degraded the sound and would like to use it without a transformer. Anybody got any info on this? I have read the manual front to back and it says this amp is configurable to high power low impedance output and that's how I have it set up, so do I still need a step down transformer? :confused:
thanks for any help