ground loop

ground loop problem happend for my friend system.
when he turn on krell kav 300il, a hum/buzz is audible in both speakers.
cdplayer is nad c541i. NAD chassis were connected to earth.

please help for eliminating ground problem.
Thanks

 

If you have added the earth connection to the NAD (ref your previous thread on the subject), remove that connection. Otherwise plug them into separate mains outlets to see if that solves the problem.

 

I do but problem not solved.
Problem is from krell because when cdplayer is not connected to amp hum exist on both speakers.

 

Are you sure it's mains hum? Could it not be sawtooth from the powersupply rectification?

 

I disconnected all cables from amp and just turned on amp.
hum/buzz were in both speakers, i think problem is main.

 

I had the same problem using the 300i with a marantz cd player.
Try a small length of speaker cable,bear both ends and loosen a case screw on both the amp + cd player.Secure the cable to both pieces of equipmant.
Not an ideal answer but it worked for me.
I now use a different cd player with balanced connections and I have no problems with ground loops.

 

If it's happening just from the amp then it's power supply related. Is it hum (smooth sound, sinusoidal) or buzz (rough sound, sawtooth)?

 

It's buzz that come from tweeter

 

Sounds to me like the amp is faulty.

 

can you tell me what happend to my amp?

 

try running a long extension cord to the amp from a socket in a different room.

You may be finding its other electrical equipment causing an earth loop/ interference.

 

what means long extension cord?

 

Hi,

I don't really know the configuration of the Krell 300i, however if it has balanced XLR and single ended RCA inputs which one are you using?

If you are using the single ended RCA, are you using the 'shorting pins' that Krell supplies for the unused balanced XLR sockets.

Have a look in the user manual it is explained in detail.

Ken

 

no i don't use shorting pins, it was not in krell box

 

where are you isaac? you should help me

 

Amir,did you read my post above?
This sounds exactly the problem - when I used balanced connections the hum disappeared (as it did when I earthed the amp with the cd player) - try it,you got nothing to lose.

I didn't get the shorting pins from Krell either.
Perhaps these only come with the power amps,not the integrateds ?

 

Thanks legzr
My friend cdplayer has no balance output.
It's not good that krell sound is noisy

 

no body could help me?

 

Earth the chassis together,cd player to amp.
It works.
Just bloody try it

 

Legzr,
I think Amir is saying the noise is still there when he has everything else disconnected i.e the noise is coming from the amp alone.
I think I have this problem with my A400, get a buzzing through the speakers that varies when I switch between sources. The noise when I switch to phono is more of a hiss than the buzz I get, through the driver, when I switch to CD.
I might have to get this sorted as my lady gets annoyed at the sound when dozing off, it gets on my nerves a bit aswell tbh, especially as my housemates Aiwa piece of crap emits no noise at all.
Is this to do with age of capacitors etc?
HM