# night night amp...



## audioslavematt (Aug 25, 2006)

Background: We teach our techies in a not for credit class that runs for two hours in the evening over the course of two or three weeks every year. We always start the class out by flexing our tech muscles and showing what we have. Then each session runs about an hour of class work and an hour of hands on training.

Last night was the first night. We decided to have a band come play. I started up the system, plugged in my iPod, and went down to finish the stage. On my way down to the stage, I noticed part of the stereo image was missing. I just wrote it off as a loose connection with my cheap 1/8" to RCA adapter. I finished the stage and investigated farther. Okay, there's signal going to both sides. Off to the amp rack, maybe one of the idiot follow spot guys shut off one of my amps to be funny. 

Backgroundx2: I have a 5.1 Dolby set up with EAW mk2194s hung 3 per side for mains and two per hang for the rears. My center channel is a pair of AS690s. These are all driven by Crown K1s. The subs are SB180s and are driven by a pair of Crown K2s.

I climb the ladder up to the blower room and of course, there's an amp off. Wait a minute, the switch is on. Outlet has power and fuse is good. Not a good way to start off the tech class. The master electrician hears my cussing and comes up to investigate. The facility manager and I decide to swap the amp for the rears with the blown amp, which was supposed to be driving the short cabinets. After 25 minutes and several broken terminal nuts, the amps were swapped and we were able to continue with our lives. Of course, I got to get my yearly dose of feedback during lab stations. Thank you freshmen.


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## dvsDave (Aug 26, 2006)

audioslavematt said:


> Of course, I got to get my yearly dose of feedback during lab stations. Thank you freshmen.



haha... we used to stand behind the freshman and tweak the amps up just a bit until that magical point of feedback and see how long it would take them to either figure what we'd done or track down the offending mic.


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## audioslavematt (Aug 26, 2006)

The facility manager has this thing for ringing out mics by routing them to the mains, throwing the faders up to +10 and cranking the gain until you get some ring. Last year I made the mistake of using a condensor mic for this station. One kid did everything right, he just forgot to apply the phantom power until after the gain knob was up all the way. Not only get we get a nice thump from the subs, but bleeding ears from the arrays. Never again.


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