Listen I just had the worst night of my life.
I finally got my garage to fill up for a music show and then
2 hours in a loud crackling noise sounded... I looked to the right and fire was bouncing around inside of my amplifier (or a spark)... Then my speakers went out...
If this isn't enough, I said "O.k, b/s, amp is bad"... "I'll get my second one one sec guys! The party will go on"...
Then 20 minutes in on my SECOND amplifier it bursts into flames almost identically!!! The right channel completely toasted (all safety lights on)...
This was horrendous, expensive, scary, and embarrasing. I ruined my first "show" that people were in to...
What went wrong? How can I prevent this in the future when I get new amplifiers...
My bass amplifier on the same power outlet never blew up though ... Thank god... That one is 2400 RMS and I love it sooooo much...
1. My outlet?
2. Wired speakers wrong?
3. wut?
I finally got my garage to fill up for a music show and then
2 hours in a loud crackling noise sounded... I looked to the right and fire was bouncing around inside of my amplifier (or a spark)... Then my speakers went out...
If this isn't enough, I said "O.k, b/s, amp is bad"... "I'll get my second one one sec guys! The party will go on"...
Then 20 minutes in on my SECOND amplifier it bursts into flames almost identically!!! The right channel completely toasted (all safety lights on)...
This was horrendous, expensive, scary, and embarrasing. I ruined my first "show" that people were in to...
What went wrong? How can I prevent this in the future when I get new amplifiers...
My bass amplifier on the same power outlet never blew up though ... Thank god... That one is 2400 RMS and I love it sooooo much...
1. My outlet?
2. Wired speakers wrong?
3. wut?
An Ashly CFT 1800
and back up PYLE PTA 1400
I believe it was the same channel each time, but I also believe the whole amp shut down (both of them motionless)... But I'm scared to turn them on.
The input was unbalanced RCA to a DJ mixer, unbalanced from DJ mixer to active crossover... Then unbalanced active crossover to amp.
The speakers were one 8 ohm pyle 10" horn / woofer daisy chained to
an old school radio shack 8 ohm of the same sort. (250 rms pyle, 250 rms radio shack)
The cabling was just speakerwire.
My only guess is I messed up the daisy chaining somehow? and that would explain it frying both amplifiers... I mean how cruel is that? Would something like that result in blowing an amp up?
The power outlet used was run to a power strip and all three of my amplifiers were running off of it...
and back up PYLE PTA 1400
I believe it was the same channel each time, but I also believe the whole amp shut down (both of them motionless)... But I'm scared to turn them on.
The input was unbalanced RCA to a DJ mixer, unbalanced from DJ mixer to active crossover... Then unbalanced active crossover to amp.
The speakers were one 8 ohm pyle 10" horn / woofer daisy chained to
an old school radio shack 8 ohm of the same sort. (250 rms pyle, 250 rms radio shack)
The cabling was just speakerwire.
My only guess is I messed up the daisy chaining somehow? and that would explain it frying both amplifiers... I mean how cruel is that? Would something like that result in blowing an amp up?
The power outlet used was run to a power strip and all three of my amplifiers were running off of it...
one think is that you actually send to or connected to the output of the left ch. together with the output of the right channel
if the level and music they play is absolutely identical (Theoretical approach) you might gate away with it ... now if the level of any channel is lower then this channel becomes from an amplifier to a load for the other channel....
Also to answer your next question and that will be
"""why the protection didn't kick in ?"""
Cause the protections are designed to detect a number of things except music .... if its music that you want they let free to pass .... In your case... music coming from the other channel is simply undetectable
kind regards sakis
if the level and music they play is absolutely identical (Theoretical approach) you might gate away with it ... now if the level of any channel is lower then this channel becomes from an amplifier to a load for the other channel....
Also to answer your next question and that will be
"""why the protection didn't kick in ?"""
Cause the protections are designed to detect a number of things except music .... if its music that you want they let free to pass .... In your case... music coming from the other channel is simply undetectable
kind regards sakis
Sakis may be on to something. I almost had a disaster with a situation similar to what he described. I was testing a phono preamp and I had one the positive inputs from one channel on the common negative. Fortunately I could smell something was getting really hot and shut it down. Amp was just about to the point where it was too hot to touch. Protection did not kick in and it actually did not sound horrible. I am sorry for your loss.
Since the fault occurred in the same channel I'd suspect an impedance drop or short in the cabling or the speaker. Check with a DMM to see if the left and right are the same and I'd suggest the DC resistance should be no lower than 3ohm if the speakers are wired in parallel (an 8ohm nominal speaker often has about 6ohm DC resistance), and should be quite a bit higher if wired in series. I would suspect you likely used a parallel connection, amplifier positive to speaker positives and amplifier negative to speaker nagatives. With a seies connection one speaker shorting out wouldn't likely toast the amp. If the cabling is pinched or stapled you should be able to determine that by disconnecting the speakers and checking just the wire with a DMM.
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I do not know much "tech talk" outside of very very basics...
Most of the posts above need to be translated to my level (a dumb persons level)
I just don't want to blow more amps...
And someone googling for this may gain help if they are in my same situation...
Would "power conditioners" have saved my problem? Also... What's the cheapest way to get new reliable amps.. any recomendations?
Hi ltjenkem,
In your diagram you mentioned the amplifiers were searing hot when they failed. You have a huge warning sign there! Nothing "likes" to be run at high temperature. In fact, the failure rate increases exponentially with each 10°C of temperature rise. Something to think about.
Power bars. Power bars and old electrical wiring that may even be questionable. You had three power amps plugged into that setup? If any of these amps used a switching power supply, the AC voltage probably dropped. That caused the switching supply to draw far more current than is normal and overheat the board and interior of the amplifiers. Boom.
You speaker wiring is fine from what we can see in your diagram. I doubt that itself caused the damage. Watch speaker and amplifier ratings. Most speaker power ratings are pure fiction. I've seen tons of burned out woofers over the years, burned tweeters are rare when the amplifier output is so much greater than the true speaker power ratings. But what of an amp that claims to be "2 ohm stable"? What that really means is that the amp is rated for 4 ohms, not 2 ohms. It may be able to survive occasional impedance dips down to 2 ohms or a bit lower, but not as a nominal load!
Good luck with your amplifiers, you will need a cabinet with far better airflow (cooling). You will also need to use the proper speaker drivers and boxes. As Brian mentioned, shorted speakers can easily cause a power amp to fail. Protection circuitry does have limits, you exceeded them.
-Chris
In your diagram you mentioned the amplifiers were searing hot when they failed. You have a huge warning sign there! Nothing "likes" to be run at high temperature. In fact, the failure rate increases exponentially with each 10°C of temperature rise. Something to think about.
Nope. Using a power conditioner with high powered amplifiers will most likely make this problem worse than the one I'm about to mention to you.
Power bars. Power bars and old electrical wiring that may even be questionable. You had three power amps plugged into that setup? If any of these amps used a switching power supply, the AC voltage probably dropped. That caused the switching supply to draw far more current than is normal and overheat the board and interior of the amplifiers. Boom.
Sure thing. The least expensive way is to buy and use good quality amplifiers. To keep them running at the lowest cost, only have professional audio service people work on your amplifiers. Cut rate technical help produces poor workmanship and incomplete service jobs.
You speaker wiring is fine from what we can see in your diagram. I doubt that itself caused the damage. Watch speaker and amplifier ratings. Most speaker power ratings are pure fiction. I've seen tons of burned out woofers over the years, burned tweeters are rare when the amplifier output is so much greater than the true speaker power ratings. But what of an amp that claims to be "2 ohm stable"? What that really means is that the amp is rated for 4 ohms, not 2 ohms. It may be able to survive occasional impedance dips down to 2 ohms or a bit lower, but not as a nominal load!
Good luck with your amplifiers, you will need a cabinet with far better airflow (cooling). You will also need to use the proper speaker drivers and boxes. As Brian mentioned, shorted speakers can easily cause a power amp to fail. Protection circuitry does have limits, you exceeded them.
-Chris
I repeatedly see similar statements in many posts/threads.
Thanks for pointing out that "stable into 2r0" is not the same as recommended to drive a 2ohm reactive speaker.
We need to educate the Membership in how to read specifications.
But who's responsibility is it to be educated?
Your drawing shows parallel connection of the speakers. If the drawing is correct you don't have the amps hooked together in disastrous parallel amp scenario mentioned. You need to read at least the DC ohms of the wiring as seen by the amp outputs with a meter. Check meter calibration against a 4 ohm 10% resistor as a battery just a little bit tired will make the 200 ohm scale read high (and falsely safe). On any ordinary amp the total load on one channel should be no less than 4 ohms. Certain amps can handle 2 ohms, read the specifications carefully as mentioned. Certainly if an amp blows, read the wiring and speaker resistance at the amp speaker terminals before hooking up another one. If the wiring was hooked over a nail or pierced by a staple as stated above, then that could have been the short. Also, a speaker could have shorted. I've blown two tweeters and no woofers over the years, so suspect everything. Crossover components in the speaker can also fail, as can protection components.
The one amp failsafe against wiring errors is a tube amp with transformer output where a 1000 ohm 1 w resistor has been soldered across the back of the speaker output terminals. However, carrying around tends to break the tubes, so they are no good for pro PA work.
The one amp failsafe against wiring errors is a tube amp with transformer output where a 1000 ohm 1 w resistor has been soldered across the back of the speaker output terminals. However, carrying around tends to break the tubes, so they are no good for pro PA work.
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Hi Andrew,
That tidbit of information is also normally included with the explanation that warranty is not insurance. This can be an energetic discussion with some people.
To answer your rhetorical question,
it is of course the responsibility of the amateur user. If the equipment is being used in a commercial setting, the principle owners of the company have that responsibility. Of course, the industry itself needs to fess up to conducting questionable marketing. Also, some factual information should be included with every piece of equipment in addition to the soon to be litter labelled "owner's manual".
Too bad society in general has become used to making problems someone else's problems.
-Chris
That tidbit of information is also normally included with the explanation that warranty is not insurance. This can be an energetic discussion with some people.
To answer your rhetorical question,
,
it is of course the responsibility of the amateur user. If the equipment is being used in a commercial setting, the principle owners of the company have that responsibility. Of course, the industry itself needs to fess up to conducting questionable marketing. Also, some factual information should be included with every piece of equipment in addition to the soon to be litter labelled "owner's manual".
Too bad society in general has become used to making problems someone else's problems.
-Chris
Hi ltjenkem,
Amplifiers connected together generally fail next to instantly. Same goes for two (or more!!) channels connected together on the same amplifier. It never ceases to amaze me what people can dream up on their own.
I don't think you did this, but it seemed like a good time to mention it.
Ever see flames shoot out every opening in an amplifier? One fella did after bringing up the inputs and outputs from an Amcron power amp on a patch bay. Plugged an output into an input. Oops! Even the PCBs had giant holes burned through them. I did repair it, but it weren't cheap! Anything you can think of happening to an amplifier has happened - somewhere, sometime.
-Chris
Amplifiers connected together generally fail next to instantly. Same goes for two (or more!!) channels connected together on the same amplifier. It never ceases to amaze me what people can dream up on their own.
I don't think you did this, but it seemed like a good time to mention it.
Ever see flames shoot out every opening in an amplifier? One fella did after bringing up the inputs and outputs from an Amcron power amp on a patch bay. Plugged an output into an input. Oops! Even the PCBs had giant holes burned through them. I did repair it, but it weren't cheap! Anything you can think of happening to an amplifier has happened - somewhere, sometime.
-Chris
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