ground loop?

I just got my 2 Altec 9440 amps back from being rebuilt and they have hum. I checked to make sure they had Good Grounds, everything checks out fine, I disconnected all the inputs and just left the speakers hooked up and they still have hum, looks like they're going to have to go back to the shop is there anything else that I can check that I may have missed?

Does it have a 3 prong plug? might be worth trying a 3 to 2 adapter but do not connect the ground wire to the outlet
Does the Amp have a 2 prong plug? try flipping over.
Is the outlet wired properly?
How are the other pieces of hardware connected? are they all grounded to the same point? or are plugged into different outlets.
 
Thanks for responding with suggestions ejc1, I did try it with no ground connected and I still had the same results. the amps originally came with a grounded power cord, I checked the receptacle in the wall, it is wired correctly and it has a ground. the only thing I didn't do as you suggested was to flip the power cord. I took both amps and put them back in the shop I'm still waiting for them to be reworked, one thing I did do was I put them up against a crown ce2000 amp, the Altec 9440 amp blew Crown amp away, the Altec makes more Bass and just sounds so much better. The crown amp is rated 1320 amps and the Altec is rated at 800 amps bridged, so when I turn the volume up and got the meters on the Altec showing 50%the Crown amp clipping light comes on, I love these old altec amps,they were made to perform
 
make sure you get them all

So that would include things like a microwave, dishwasher, refrigerator, washing machine and so on.

If so that is not necessarily the best idea in terms of safety. It will also defeat the intended purpose of any ground fault interrupter outlets/breakers that may be in use.
 
So that would include things like a microwave, dishwasher, refrigerator, washing machine and so on.

If so that is not necessarily the best idea in terms of safety. It will also defeat the intended purpose of any ground fault interrupter outlets/breakers that may be in use.
ive been doing it for 10 yrs no prob.... and yes all have to be gone in the house, only one will cause the ground loop... I was so happy to get rid of that noise ;))
 
Hi all, I have another issue which i think is a ground loop problem.I hooked up tuner,preamp,amp and 2 speakers,got loud buzzing in speakers.I thought is was the cable i made(per other topic here PREAMP ISSUE) but that was not it. I unhooked all, just left amp and speakers connected to each.Amp only has 2 rca inputs and hi level speaker connections.Kenwood km-893 amp. With the amp on i have input cables plugged into amp going to nothing,when i touch the + of the rca input i get the loud buzzing,or if i hook it up to anythig even with another component unplugged and off same buzzing??? THANK YOU













+
 
ive been doing it for 10 yrs no prob.... and yes all have to be gone in the house, only one will cause the ground loop... I was so happy to get rid of that noise ;))
you have a big problem that is probably small .. get your house wiring checked right away and your appliances ..removing grounds from appliances is downright dangerous and should never be done under any circumstance . it is their for your safety .
i do suspect the house ground is missing or a bad neutral connection
 
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Hi all, I have another issue which i think is a ground loop problem.I hooked up tuner,preamp,amp and 2 speakers,got loud buzzing in speakers.I thought is was the cable i made(per other topic here PREAMP ISSUE) but that was not it. I unhooked all, just left amp and speakers connected to each.Amp only has 2 rca inputs and hi level speaker connections.Kenwood km-893 amp. With the amp on i have input cables plugged into amp going to nothing,when i touch the + of the rca input i get the loud buzzing,or if i hook it up to anythig even with another component unplugged and off same buzzing??? THANK YOU













+
get rid of all three prongs throughout the house........ cant leave even one......
 
Please, those reading this thread, do not remove all of the ground connections all over your house. Regardless of what one person may have done, it is not safe. It will defeat any ground fault interrupters and raise the risk of shock, period, one and done.

There is a reason why those ground connections exist. There is a reason for GFCI outlets and breakers. It is called safety, one and done.
 
Hey all. i was just screwing around with this ground,loud hum issue.I ran a ground wire from tuner to preamp,then touched the other end to amp chassis and loud hum went away,just good clear loud music.I have a problem since i did this,my preamp volume will go up but not down.IT is lighted all the light stay on like the volume is all the way up.
This problem only since i added the gound wire,so i disconnected the ground from the preamp.This did not help.The ground is just from tuner to amp chassis,not hooked to nothing else and hum buzz is gone. ??? THANK YOU
 
It is cheap way to raise one's risk of electrical shock. Just because one person has done it does not mean that it is right.

This is just a straw man response.

That is like a a person that has driven drunk for 10 years telling you that they have done it for 10 years so it is okay and safe.

This is not rocket science. Ground connections and GFCI outlets (which the removal of the ground will defeat and cause not to work) have a specific function. That is to offer protection from electrical shock and possible death.

To recommend this indicates a lack of understanding.


No matter what a person says, this is not a good idea. End of story, period, one and done.

Will doing this immediately result in a shock hazard, likely not, but it removes a very important layer of protection.

I understand that I am being repetitive, but this after all a sticky. Those that might just be starting out in this hobby and even others with out experience with electricity will read these posts and might follow this dangerous information.
 
thanks all,i will play around with this on the weekend. Like i said its just the preamp working weird.This could just be a ground issue?? Its odd that i cured one problem but made another problem. THANK YOU
 
Please, those reading this thread, do not remove all of the ground connections all over your house. Regardless of what one person may have done, it is not safe. It will defeat any ground fault interrupters and raise the risk of shock, period, one and done.

There is a reason why those ground connections exist. There is a reason for GFCI outlets and breakers. It is called safety, one and done.
been doing this for 15 YEARS never shocked,, no fires,,,, guess what fool im still alive... snowflakes worry too much.... LOL !!
 
Yes, just like the drunk driver that has never had an accident, that of course makes drunk driving okay for everyone.

You need understand basic logic.

Okay. If what you are recommending is the thing to do, please explain the purpose of the ground side of the AC mains. Why have it in the first place? Why have GFCI outlets and breakers? Why did residential AC mains wiring go from non grounded wiring to grounded wiring?

What happens if a device has an internal fault that places dangerous voltage on exposed metal parts, microwave, refrigerator, clothes washer, window AC and so on?

Are you saying that the above has never, ever happened?

Again, just because you have done it does not mean that is it the right thing to do, or that someone else will have the same results.

BTW, the National Electrical Code (NEC) requires that all exposed metal on equipment and appliances be connected to an equipment grounding conductor.

An insurance company may take a dim view of your recommendation in the event of an issue (electrical shock, fire and so on).

For those that are interested in electrical safety, and it appears that some are not here is a link with a very simple explanation and even some simple diagrams.

Link to why grounding for safety is important. Look at the second diagram. Without proper grounding, electricity through your body, electrical shock and possibly death. It is just this simple.

Of course some without a basic understanding of electrical safety will say that the information referenced in the above link is incorrect and should be disregarded and suggest that it is okay to remove the ground connections from every electrical device in the home.

Of course, one can be like the drunk driver that has not had an accident in 15 years and tells everyone that drinking and driving is okay because he has never had an accident. Never mind reality.

BTW, my verbal skills preclude the necessity of name calling to make a point.
 
More name calling to make a point.

And we lived without stringent laws regarding drunk driving, your logic does not hold water.

History is full of things that we did one way. Over time we found safer ways to do these things.

So are you telling all of us that the NEC is totally wrong with its requirement for safety grounding?

Back in the day, cars had mechanical brakes, then came hydraulic brakes, then came dual master cylinders for increased safety. By your logic if the brake line going to the front wheels is leaking or your car pulls to the left when using the brakes, you would recommend disconnecting the master cylinder for the front wheels instead of correcting the actual problem.

So what? We lived with single cylinder master cylinders for years. Dual master cylinders save lives.

The list of safety improvements over time is almost limitless. Using procedures from back in the day to make you point is faulty logic.

Again, answer my question, are you saying that no one has ever been shocked or electrocuted by a device without proper grounding? Are you saying that proper safety grounding has never prevented electrical shock or electrocution?

If so show me the numbers.


Correct grounding helps to prevent electrical shock and even death due to electrical shock.
 
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