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usernamebob
New member
the speaker output is designed to drive a speaker (hence the name).. it's sorta like plugging mains power into your hearing aid
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xstatic
New member
Speaker outputs are measured in watts. The actual current required by line and mic inputs would be measured in milliwatts. A speaker outout at a low level would be sending hundreds of times the power that is expected by a mixing console.
Hubba, even if you were using the wrong output from the Marshall, it SHOULD NOT have fried the Marshall head. It also shouldn't have taken out the whole circuit. There is a much better chance that the problem was something in the head itslef, or even more likely in the AC in whatever location you were at. It is very possible that it was pure coincidence that the circuit went just as you were plugging into your console, or quite possible that either the AC or the head was poorly grounded and you touching the plug to your mixer bridged that ground therefore tripping the circuit. Either way they were not your fault. What Marshall head are we talking about here? I would love to take the old one off your hands for a fair price
Hubba, even if you were using the wrong output from the Marshall, it SHOULD NOT have fried the Marshall head. It also shouldn't have taken out the whole circuit. There is a much better chance that the problem was something in the head itslef, or even more likely in the AC in whatever location you were at. It is very possible that it was pure coincidence that the circuit went just as you were plugging into your console, or quite possible that either the AC or the head was poorly grounded and you touching the plug to your mixer bridged that ground therefore tripping the circuit. Either way they were not your fault. What Marshall head are we talking about here? I would love to take the old one off your hands for a fair price
Farview
Well-known member
Xstatic did a good job of explaning why not to use the speaker output.Pughbert said:
As far as the AC being wired backwards, most things will work fine if plugged into a miswired outlet. But Lord help you if you hook something plugged into a miswired outlet up to something plugged into an outlet that is wired properly. If you throw a bad ground (or no ground) on top of that, call the fire department and an ambulance.
SonicAlbert
Super-Sonic "Herb" Albert
You can get a simple little circuit tester device from Radio Shack for about $5. Plug it into the wall outlet and it shows you how the circuit is wired and if it is wired correctly. Worth having. Mine is years old, but the catalog number is 22-101.
thediscoking
New member
I don't think that going from the speaker out to your mixer would blow the Marshall. If anything, I believe it would screw up your mixer......
If the Marshall has an effects loop that the guitarist is not using, you can probably use that, depending on how it's normaled.
It sounds like the power surge blew the amp when the power came back. If power ever goes off, TURN OFF AMPLIFIERS!!! This will save you a lot of hassle.
While we're on the subject, as far as electricity goes..... in most modern buildings, most walls have different curcuits. If you distribute your power thoughout the room instead of powering everything from a single outlet, that will make a world of difference. Amps usually draw the most power. Powering them up one at a time, instead of all at once, will help. Manuals will also tell you what the draw is.
Of course, all buildings are wired differently.
Good luck!
Jacob
If the Marshall has an effects loop that the guitarist is not using, you can probably use that, depending on how it's normaled.
It sounds like the power surge blew the amp when the power came back. If power ever goes off, TURN OFF AMPLIFIERS!!! This will save you a lot of hassle.
While we're on the subject, as far as electricity goes..... in most modern buildings, most walls have different curcuits. If you distribute your power thoughout the room instead of powering everything from a single outlet, that will make a world of difference. Amps usually draw the most power. Powering them up one at a time, instead of all at once, will help. Manuals will also tell you what the draw is.
Of course, all buildings are wired differently.
Good luck!
Jacob
A
astoebe
New member
Please Read
one more time 'cause no one seems to understand what I am saying
ONE TIME I ACCIDENTALLY PLUGGED THE SPEAKER OUT INTO A MIXER FROM A MARSHALL HEAD, AND THE HEAD BLEW NOT THE MIXER CHANNEL OR MIXER IN GENERAL. It's really a true story, I promise, I'm not lying. I would think that the mixer would blow too, but it didn't the head did. So....I think it is entirely possible that he plugged the speaker out into the mixer and blew the head.
one more time 'cause no one seems to understand what I am saying
ONE TIME I ACCIDENTALLY PLUGGED THE SPEAKER OUT INTO A MIXER FROM A MARSHALL HEAD, AND THE HEAD BLEW NOT THE MIXER CHANNEL OR MIXER IN GENERAL. It's really a true story, I promise, I'm not lying. I would think that the mixer would blow too, but it didn't the head did. So....I think it is entirely possible that he plugged the speaker out into the mixer and blew the head.
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xstatic
New member
Sure, nothing is impossible. It is also entirely possible that you were a victim of circumstance. Maybe a cap was already about to go. Maybe you bridged two grounds at the same time when you touched the mixer and that put enough stress on the already failing cap which in turn blew and quite possibly was the casue of something else blowing in the amp. There are so many possibilites. In my experience as a system tech, you always start with the most obvious of possibilites and work your way down to the extremely unlikely ones. This saves a lot of time for one, and more often than not saves you from misdiagnosing what the problem is. Not only that, but if you misdiagnose a problem and only treat one of the symptoms of the problem, it is likely that you will have the same problem again soon.
When you are dealing with bad AC, it is often hard to spot that problem. I found a bad circuit in an old theatre the other day. The guitar player got shocked when he touched his microphone. This is not uncommon if the guitar player has his amp plugged into another ciruit than the PA is with an uncommon (non isolated) ground. Usually though, it results in more of a static type pop. Brief and instantaneous, but often can be fairly painful, especially if you are just about to sing and you get zapped in the teeth. This however was different. When I touched the mic there was a small but steady current that you could feel pulsing. It was subtle though and if he were to have been holding that mic in his hand and doing something else at the same time, he may not have actually noticed it. If he had been holding that mic in one hand and turned his guitar volume up and touched his strings, he could easily have sent a new voltage directly to the input of his guitar amp, which if it had not been in standby, who knows what could have happened? If this had resulted in frying his amplifier, and he did not notice that the mic had been passing voltage, this could have been a real bugger to track down in a hurry and other damage could have been done before the problem was solved. A problem like this is not that common (at least with a severe enough voltage to actually feel a steady pulse). It is unlikely, but certainly possible.
When you are dealing with bad AC, it is often hard to spot that problem. I found a bad circuit in an old theatre the other day. The guitar player got shocked when he touched his microphone. This is not uncommon if the guitar player has his amp plugged into another ciruit than the PA is with an uncommon (non isolated) ground. Usually though, it results in more of a static type pop. Brief and instantaneous, but often can be fairly painful, especially if you are just about to sing and you get zapped in the teeth. This however was different. When I touched the mic there was a small but steady current that you could feel pulsing. It was subtle though and if he were to have been holding that mic in his hand and doing something else at the same time, he may not have actually noticed it. If he had been holding that mic in one hand and turned his guitar volume up and touched his strings, he could easily have sent a new voltage directly to the input of his guitar amp, which if it had not been in standby, who knows what could have happened? If this had resulted in frying his amplifier, and he did not notice that the mic had been passing voltage, this could have been a real bugger to track down in a hurry and other damage could have been done before the problem was solved. A problem like this is not that common (at least with a severe enough voltage to actually feel a steady pulse). It is unlikely, but certainly possible.
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acorec
Banned
The Marshall amps output transformer (the one that drives the speaker output!) is fried. About $40. I have fixed way too many and it is always the same problem. They go because of what this guy did, or they go just sitting there looking at them, but mainly when you plug the speaker output to anything BUT a speaker. With other OPE (other peoples equipment) I "just-say-no" to any plugging or unplugging. I never touch it period. I hand them the cord and make sure that they plug it in correctly to protect my equipment, but I never could stand morons who have to assign blame to any and all problems. I have seen these output transformers go in front of my eyes in a quiet, non-eventfull manner.
mshilarious
Banned
Hubbawho said:
If you touched the tip of the plug to the ring on your mixer, then the speaker out from the amp would be shorted to ground. I assume amps have some sort of protection against that sort of problem, but maybe in your case it somehow didn't.
It's generally a good practice not to plug and unplug speakers with the power amp on.
Also, hire an electrician to wire up adequate power in your studio.
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mbenny123
New member
Hmm, I disagree. In most modern homes, all the outlets in one room are on the same circuit. At least where I live. Also, you want all your audio equipment to be on the same circuit anyways, to avoid ground loops.
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xstatic
New member
In many homes, bedrooms and bathrooms are all one circuit and rooms like the kitchen have more.
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mbenny123
New member
xstatic said:
True, the refridgerator and microwave outlets will usually each be on their own circuit, separate from the other outlets.
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acorec
Banned
acorec said:
If the amp is tripping the circuit breaker or/and blows its fuse, the output transformer is shot. Plug the amp in with a good fuse and turn it on. It should blow the fuse and/or trip the brealer/house fuse. That is the best sign it is the output transformer.
79_Les_Paul
Member
I kinda did the same thing once, setting up at an old church.....I had my amp pluged into the wall, and my keyboard plugged into the wall, when I plugged the keyboard into the amp....boom.
blew the film right off the circiut board at the output.....easy fix though, i took a 1 inch piece if wire and soldered it from each blown section.....has worked fine for over 13 years...
i suspected something screwy in that old building... none of the recepticals were three prong...ugh!
hope you can get the head fixed or sold and recoup some of your money....
blew the film right off the circiut board at the output.....easy fix though, i took a 1 inch piece if wire and soldered it from each blown section.....has worked fine for over 13 years...
i suspected something screwy in that old building... none of the recepticals were three prong...ugh!
hope you can get the head fixed or sold and recoup some of your money....