# Not computer.. Not software either..



## Scruffy113 (Aug 13, 2009)

What can be the cause for an amplifier to make humming sounds?
Mine does.. Constantly.


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## Kangamutt (Aug 13, 2009)

Feedback. You're talking about a guitar amp, right?


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## Rel (Aug 13, 2009)

Loose connection on the cord from the amp to the instrument, or vise-versa (that is usually the problem)

Other than that, it could be the speaker or a connection to the speaker


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## ToeClaws (Aug 13, 2009)

A poor quality amp, unfortunately.  The humming sound is feedback generated by the electronic components themselves.  Many computer subwoofers have a slight hum to them because of this - some worse than others.  Some affordable ones are pretty quiet, but usually you have to get into more expensive systems to eliminate it.


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## AshleyAshes (Aug 13, 2009)

Scruffy113 said:


> What can be the cause for an amplifier to make humming sounds?
> Mine does.. Constantly.


 
Electrical noise.  How many things do you have plugged into other things, all the while all plugged into the wall?


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## Kangamutt (Aug 13, 2009)

Cell phones as well. If you have it sitting near speakers, it can make some noisy interference.


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## Scruffy113 (Aug 13, 2009)

This is a good old NAD 20 series amplifier, not neccesarily for instruments.

I don't see how feedback would make a _humming _sound.



AshleyAshes said:


> Electrical noise.  How many things do you have plugged into other things, all the while all plugged into the wall?



Lots'a stuff, but same shit happens no matter where I am and how many things I've got pluggen in at the same time.


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## Scruffy113 (Aug 13, 2009)

Kangaroo_Boy said:


> Cell phones as well. If you have it sitting near speakers, it can make some noisy interference.



Not like that kind of sound.


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## LizardKing (Aug 13, 2009)

Unplug all input, see if it's still there. 
Plug back in one at a time, see when it reappears.
???????
RAPTOR JESUS


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## Hir (Aug 13, 2009)

Both a poor quality amp and jack lead. A jack if not high quality can cause reception from the outside to effect the quality.

Also poor quality distortion/digital effects can tamper with the humming you hear.


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## Scruffy113 (Aug 13, 2009)

Okay, let me tell you something real quick.
It's the amplificator, not the jacks or speakers. The humming is there constantly, no matter what input OR output I use. This amp is OLD, like at least 20 years old.


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## Hir (Aug 13, 2009)

Then you need a new amp.


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## Scruffy113 (Aug 13, 2009)

DarkNoctus said:


> Then you need a new amp.



Where the hell am I supposed to find an amp that has phono settings nowadays?

Not in Norway, and I can't order one from the U.S, because of your stupid laws.


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## Hir (Aug 13, 2009)

Scruffy113 said:


> Where the hell am I supposed to find an amp that has phono settings nowadays?
> 
> Not in Norway, and I can't order one from the U.S, because of your stupid laws.


My stupid laws?

I'm from the UK, thank you very much. Good job assuming where I live.


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## Scruffy113 (Aug 13, 2009)

DarkNoctus said:


> My stupid laws?
> 
> I'm from the UK, thank you very much. Good job assuming where I live.



*'Your'* doesn't necessarily mean _a _certain person's something.


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## ToeClaws (Aug 13, 2009)

There are plenty of amplifiers still available with "Phono" jacks - remember that real audiophiles will most definitely have a record player in their collection (since they sound much better than CDs).  The caveat though is that these amps are very expensive.  Some do have smaller models though, so might be worth having a look.  Here are some Canadian ones that should export to you:

http://bryston.com/

http://www.simaudio.com/main.htm


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## ArielMT (Aug 13, 2009)

http://global.ebay.com/ - Select Norway as your country.

There's a UK seller listing a NAD 3020 amp, and the bid was just under 300 kr as I wrote.  (Shipping's another 250 kr though.)


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## Irreverent (Aug 13, 2009)

Scruffy113 said:


> This is a good old NAD 20 series amplifier, not neccesarily for instruments.



So we've ruled out cheap..... 

Bad power could the cause.  What else is on circuit with the amp?


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## Scruffy113 (Aug 14, 2009)

Irreverent said:


> Bad power could the cause.  What else is on circuit with the amp?



A Mac Mini, a SNES, a Wii, a Samsung 32" LCD, some external storage devices, a record player and a DVD/radio-thingy.

However, it hums like an old guy does when he remembers a song he used to listen to when he was young, anytime, anywhere, no matter how many other things are plugged in the wall at the same time.




Irreverent said:


> So we've ruled out cheap.....



Instead of bying an amp myself, I got it from my step-mother, who didn't have any use for it anymore.
I wouldn't say "cheap", I'd rather call it "being smart".


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## Irreverent (Aug 14, 2009)

Scruffy113 said:


> A Mac Mini, a SNES, a Wii, a Samsung 32" LCD, some external storage devices, a record player and a DVD/radio-thingy.



All of which have external powerpacks that might be introducing noise onto the line.



> However, it hums like an old guy does when he remembers a song he used to listen to when he was young, anytime, anywhere, no matter how many other things are plugged in the wall at the same time.



Has it been cleaned out?  Air dusted and contact cleaner on all of the buttons and knobs might help reduce the hum.  I seem to remember NAD's of that era being sensitive to dust.



> I wouldn't say "cheap", I'd rather call it "being smart".



Agreed, but when that NAD was bought, it was probably one of the most expensive on the market at the time.


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## Scruffy113 (Aug 14, 2009)

Irreverent said:


> Has it been cleaned out?  Air dusted and contact cleaner on all of the buttons and knobs might help reduce the hum.  I seem to remember NAD's of that era being sensitive to dust.



My dad suggested months ago, so we cleaned a bit, but it didn't seem to help much. :/



Irreverent said:


> Agreed, but when that NAD was bought, it was probably one of the most expensive on the market at the time.




... :3


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## Irreverent (Aug 14, 2009)

Scruffy113 said:


> My dad suggested months ago, so we cleaned a bit, but it didn't seem to help much. :/



An overhaul at at stereo shop would be a proper clean, but expect to wait 6-8 weeks to get it done.  It might just be the best that MOSFETS of that era could do.

Do you have the matching cd player that went with that amp?  Its the one that (in typical NAD fashion) only had three buttons and a single segment LED for the track number.  On, open and play.  They were oh so minimalist back then.


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## Rakuen Growlithe (Aug 14, 2009)

If you get the noise only when you plug it into the computer, I'm assuming that's what you're doing, then it's probably from your plug. I had a similar problem when I tried to attach my laptop to an amp, sound is clear running on battery, lots of interference when using mains. The electricity supply isn't clean, it has a lot of 'dirt' in it and that gets picked up on the amplifier. To fix it you can apparently buy an electrical filter that will clean the electricity signal.


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## SnowFox (Aug 14, 2009)

Has it always been like this?

If its a steady sine wave type hum when nothing else is connected to it and nothing electrical is anywhere near it or it's cables, then it's probably being induced from the power transformer inside. 

It might help to ground the casing if it's not already.


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## Scruffy113 (Aug 14, 2009)

SnowFox said:


> Has it always been like this?



I have no idea. :S



SnowFox said:


> If its a steady sine wave type hum when nothing else is connected to it and nothing electrical is anywhere near it or it's cables, then it's probably being induced from the power transformer inside.
> 
> It might help to ground the casing if it's not already.



I popped up the casing and the power transformer made a sound at about the same frequency as the one that comes out the speakers/headphones/whatever even if there is nothing to output to.
So yeah, the filters supposed to remove the sound from the power transformer are now main suspects in this case.


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## SnowFox (Aug 14, 2009)

Scruffy113 said:


> I have no idea. :S
> 
> 
> 
> ...



It may just be the rectifier isn't good enough or the capacitors are wearing out. Another thought on the grounding thing... does it make any difference when poking buttons or knobs? Sometimes the solder can crack where they're fixed to the circuit board and parts might not be properly grounded causing the humming.


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## hitokage (Aug 15, 2009)

SnowFox said:


> the capacitors are wearing out.


This is the most likely. It's not a matter of them wearing out, but aging/drying out or completely failing (domed tops and/or leaking).


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