Posted by Bruce Gering on August 28, 2002

I've heard that Direct Current into a speaker will start it on fire. Sometimes when amps fail, they can go into DC mode, although most of todays designs will shut the amp down. I've also heard that real hard clipping will send an amp into DC also, which explains why the keyboardist's wedges in the previous post, and probably the club's mains started on fire.

Remember that the cones are made of basicly paper. Usually the voice coil will fry, and that is that. but if the connection keeps working, you get total meltdown. I'll bet it looked cool to onlookers!-Bruger


Posted by Jay Johnson on August 29, 2002

I had a Crown DC300A short and dump DC into a monitor about 15 years ago. Caught fire and smelled really bad. ;)


Posted by Bruce Gering on August 29, 2002

I work with a band (briefcase) that employ's a DC300A on some RH 2" exit horns. It has a nice warm sound, but it's a bit noisey. I looked at the amp and said: "Man, time for an upgrade!" The same band also uses a Crown PSA-2 on the mids (McCauley cabs w/2 JBL 15's). Although these amps are old, they keep ticking. One of these days I'll be the Hero of the Day because I always bring a spare amp. Yes, my "breifcase" looks more like a steamer trunk, but being Johnny-on-the-spot with a spare whatever will reap more rewards towards the reputation. In this line of work, it seems reputation is everything.

Bruger


Posted by Greg Cameron on August 28, 2002

I recall back in the early days of Rat Sound, seeing some very heavy guage chokes on the passive crossovers burn up and get hot enough to start a fire. Can you say overstaturation? Dave Rat told me once during an Yngwie Malmsteen show in Long Beach, the keyboard player kept giving the rising thumb for more monitors during his solos. So Dave kept cranking it.

I guess right about the time the keyboard player was happy with the levels (must have been some of the loudest monitors ever), smoke and flame started billowing from the fills. I'm sure the solo looked damn impressive to the crowd. Probably scared the crap out of the keyboard player ;-)

Greg


Posted by Lew Veldas on August 29, 2002

I had something similar happen a few years ago at a major London venue with a veteran avant-garde keyboard act. I was having a nice easy time at FOH with 2 stereo premixes from stage and a few mics for vox etc. Towards the end of the show one of the mixes came up a lot in level; OK, back off the input gains till the channels stop clipping, no problem.......

Shortly afterwards I noticed the stage rapidly filling with smoke; OK, the lampies must have started up their smoke machine......

Then I realise the smoke smells like burning glassfibre circuit boards, and it's pouring out of the wedge monitors......hey, is the monitor engineer asleep or what? As usual he's not seeing the call light on the comms, but eventually wakes up and realises what's going on. By then it's nearly the end of the set.......

Fortunately it was all smoke and no flames. I think the final score was six crossovers and four diaphragms. The owner of the hire company was not best pleased......

(but he still hasn't got any repeater beacons for the comm. system)