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Scary incident.

Doodaddy

Doodaddy

Supporting Member
Jan 11, 2005
1,542
80
West Monroe, LA
#1
SO here I was, in the middle of practice. I had just changed over from my Blue Steels over to some Sadowsky Bright Nickel Blue Label (and was absolutely loving them). I was really keying in on how things were sounding and adjusting my preamp. Forget that we were writing a song. :hmm:

I finally got every thing set and then commenced to focusing in on the song. This amazingly horrid racket started blaring from my cab and smoke was flying. My Art SLA2 was blowing smoke and shooting square waves to the cab. I lucked out and the drivers seem to be fine, but the amp is bricked. Took the casing off and the circuitry is just charred plastic now. I don't really understand why this occurred.

Anyone else had an amp go out like this? It hasn't been set up any differently in over a year and it's stationary. :bawl:
 
#2
holy crap man i am so sorry!

that is crazy!

The combo amp i have ( just for doing some practice) is a Genze Benz. its like an 8 inch speaker with tweet.

anywho, i was signing through it one day, just practing my voice and it started to funk out and BAM! Got that smell....something fried ya know?

Welp, I let it sit, and now its fine. No idea what happened.


Do you have any other amps? I have NEVER heard of an amp just charing to plastic like that for no reason.

good luck bud!

by the way, if ya need a new one, there are some sick deals at a store in mass! SWR WorkingPro 700 BRAND NEW for 599!

i think im picking up the 400 version...thats only 399
 
#3
I personally don't. In fact, the amp that burned was the church's that I play for. I just can use it at my own discretion. We actually have two rigs at the church, one being my Sansamp RBI - Art SLA2 - SWR WM4x10 or Behringer V Amp - Crown XTi 1000 (came in literally like 5 days ago) BF Tuba 48 - BF Omni Top 12.

I guess for the time being, I can just go into the XTi (Bummer hunh? lol), I just really didn't want to bother with hooking a computer up to it to change all the settings on it to just get a straight feed through it. Maybe I can talk the church into putting an XTi 2000 in my rack. :p
 
#4
Of course we can't know what happened by long distance guessing, but I did have an amp blow like that once. The manufacturer had been sold a batch of counterfeit capacitors, and one or more of them went into a bunch of amp heads which later blew up at random times. So perhaps your amp had a bad cap or two, that were either under spec the whole time and only now "chose" to expire, or which used to be perfectly good but "went bad". Caps do expire from age sometimes.
 
#5
OK, this is only a guess, I think one of 3 things happened.

1. Transformer failed. Starts shorting out, burning insulation, gets worse, you can see how this is bad.

2. Bad wiring caused a line voltage short. Burning commences.

3. Dirt caused a short along the board, but I don't think that would cause plumes of smoke and a completely toasty board.

Sorry about that dude, that sucks. :bawl::bawl: I might have to open mine up now and look for bad wiring.

Good luck shopping, I hope you get a good deal on something.

(I wanted to say smokin deal, but I thought that would be in bad taste. So I waited 'til here.:hiding:)
 
#6
I wasn't looking for specific answers. Just merely sharing an experience and seeing if anyone had anything similar.

When I'm not infuriated, I'm going to take a closer look at it. :p Surely the caps didn't expire in roughly 2 years. :(

I hope to get pics soon.
 
#7
I was going to jam with a friend once, borrowing his roommates bass and ampeg b100 combo. Turned it on, POOF! lots of smoke, lots of carbon in the amp chassis. Literally only turned the power on, never got to play a note. At least the roommate was cool and accepted that it wasn't me abusing it that caused the amp to die. Sometimes it just happens. Good thing your drivers are OK.
 
#8
Only thing I had go out in a blaze of glory like that was an old ampeg (pawn shop special). I didn't have the crazy sounds and pops, but I had plenty o' smoke.

I also had a Feder BXR years ago and it just stopped making any noise one day. Took it in and they said a couple of roaches had gotten fried to the board and shorted it out.....lol. Needless to say we did a complete "makeover" of the practice room.
 
#15
BassmanPaul said:
Sorry I can't make too much out of your photos. You were just running on one channel?

Paul
Click to expand...
8 ohm mono. I hope I can get some better pics pretty soon. I have to find a camera first. :(

I was completely content with the amplifier before it burned. It wasn't the lightest amp in the world (it feels heavier than the XTi 2000 that's in the rack right now), but I think it was just a random defect. I can't see this being a common issue.
 
#16
Doodaddy said:
8 ohm mono. I hope I can get some better pics pretty soon. I have to find a camera first. :(

I was completely content with the amplifier before it burned. It wasn't the lightest amp in the world (it feels heavier than the XTi 2000 that's in the rack right now), but I think it was just a random defect. I can't see this being a common issue.
Click to expand...

So you were running the amp at its' operational limits. It should not have failed but if it is going to fail it will when both channels are running at maximum at the same time. I would think about getting a power amp that is 2Ω per channel capable. Possibly a Carvin DCM series. Make sure there is plenty of room for cooling - that's what I think blew your SLA2, it got too hot.

Paul
 
#17
BassmanPaul said:
So you were running the amp at its' operational limits. It should not have failed but if it is going to fail it will when both channels are running at maximum at the same time. I would think about getting a power amp that is 2Ω per channel capable. Possibly a Carvin DCM series. Make sure there is plenty of room for cooling - that's what I think blew your SLA2, it got too hot.

Paul
Click to expand...

I agree. From the description of the failure, it sounds like thermal runaway of the output transistors. He's lucky it didn't take the speakers out as well.
 
#19
ggunn said:
I agree. From the description of the failure, it sounds like thermal runaway of the output transistors. He's lucky it didn't take the speakers out as well.
Click to expand...

I was kinda worried about the drivers as well. Square waves aren't exactly friendly. I heard the sound and immediately knew what was happening and hit the power switch. The saw about 3 seconds of waves. Unless the spider ripped (I didn't pull the drivers), there is no damage.

I played the cab again Sunday night and all seemed well. :bassist:
 
#20
Doodaddy said:
The amp had been in use for about 30 minutes of off and on use (song writing) and wasn't even warm. There were 3 rack spaces above it for ventilation.

The amp is stable at 8 ohm mono. There is no user error in this situation.
Click to expand...

There has been no mention of user error in any post I have seen in this thread. Using the amp in bridge mono into 8Ω should have been fine. It IS however a fairly cheap power amp and the one space form factor does not allow for a huge amount of cooling. Add that to the fact that amps DO go wrong from time to time.

How were your speakers wired to the amp and how did you connect the signal input?

Paul
 

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