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nbaptista
22-03-2008, 16:00
I think I have a ground loop in my system(only stereo,no AV or TV nearby).Do you know anything I can do (DIY) to fix it?Buying a filter,for example or something else...:confused:
BTW,my amp is allways on,so I donīt have huummm issues anymore,it just happened when I turn on the amp

WikiBoy
22-03-2008, 18:00
I think I have a ground loop in my system(only stereo,no AV or TV nearby).Do you know anything I can do (DIY) to fix it?Buying a filter,for example or something else...:confused:
BTW,my amp is allways on,so I donīt have huummm issues anymore,it just happened when I turn on the amp

I would try and help you but your post makes no sense.

1 do you know what a ground loop is

2 why do you think you have one

nbaptista
22-03-2008, 18:18
1 do you know what a ground loop is

2 why do you think you have one
1 )well , Iīve read a few postīs and Internet
2) when I turn on the amplifier,only sometimes,it appears an huummm trough the speakers during 3 or 4 minutes and after a while,the huuummm disappears!

Mike
22-03-2008, 18:21
Doesn't sound like a ground loop then, they tend to be there all the time (or at least when the offending equipment(s) are switched on) and don't just go away when your amp warms up.

Cheers,
Mike.

WikiBoy
22-03-2008, 19:32
1 )well , Iīve read a few postīs and Internet
2) when I turn on the amplifier,only sometimes,it appears an huummm trough the speakers during 3 or 4 minutes and after a while,the huuummm disappears!

You have a power supply capacitor breaking down, it needs replacing, see service engineer.

nbaptista
22-03-2008, 20:00
You have a power supply capacitor breaking down, it needs replacing, see service engineer.
Iīve called my dealer a time ago and he said to me that probably was a loop earth.What I did next was to disconnect all the other components of my system from the amplifier.So I did a test with only the amplifier connected to the speakers,and then I switch of and on the amplifier again and again and nothing happened.The hhuuummmm was gone!So,what do you think it can be?If were a power supply capacitor breaking down,the huummm still appears,with amp connected to the speakers,no?
BTW,my CD player is a Naim CD 5 with Din,not RCA

Prince of Darkness
22-03-2008, 20:36
I am not as knowledgable as Richard, so apologies if I have this wrong.
The faulty capacitor is taking a while to charge up after switch on, therefore is initially failing to properly smooth the D.C. (the hum originates in the A.C. mains). This causes the initial hum. When the capacitor charges up the hum disapears. When the amp is switched off and back on, the capacitor does not have time to discharge so the hum does not reappear.
If the hum had been due to an earth loop it would have remained constant and not disappeared.:)

nbaptista
22-03-2008, 20:52
I am not as knowledgable as Richard, so apologies if I have this wrong.
The faulty capacitor is taking a while to charge up after switch on, therefore is initially failing to properly smooth the D.C. (the hum originates in the A.C. mains). This causes the initial hum.
But why the huummm does not appear when the amp is only connected to the speakers?

Prince of Darkness
22-03-2008, 21:30
Is this perhaps a power supply fault in one of the source components?

nbaptista
22-03-2008, 21:54
Is this perhaps a power supply fault in one of the source components?
Like in the cd player,for example?

Mike
22-03-2008, 22:39
Does the problem only manifest itself when one particular source is selected? or at all times?

nbaptista
23-03-2008, 01:28
well,most of time CD is the source selected

nbaptista
23-03-2008, 11:29
well,it is not a ground loop,I did the experienece in another room

nbaptista
23-03-2008, 15:24
You have a power supply capacitor breaking down, it needs replacing, see service engineer.
Prince of Drakness said "Is this perhaps a power supply fault in one of the source components?"
Richard,
Is he right?Please help me asap ,because I have to report this break to Densen service .I want to ship the Densen to Denmark and write a report describing the fault !

Prince of Darkness
23-03-2008, 18:10
Maybe it would be a good idea to try switching on the amp,waiting a few minutes then switching on the C.D. player (or vice versa).
Also, does the hum level vary with volume control setting? If the C.D. player is at fault, I would expect it to.

nbaptista
23-03-2008, 18:53
Maybe it would be a good idea to try switching on the amp,waiting a few minutes then switching on the C.D. player (or vice versa).

Good idea!I will try it,the next few dayīs

nbaptista
26-03-2008, 18:22
Today,I did an experience with another cd player that use RCAīs,unllike my Naim that use DIN and so far the huummm is not so loud,but it still appears for 1 or two minutes but now much more lower!But now it apperas on speakers,not trough the speakers,like some nasty frequence.
What you guyīs suggest?Is it normal,I read on some foruns that many have huummm issues related with amp transformers!

nbaptista
28-03-2008, 22:40
The amp is going back to Denmark!
BTW,is it possible to fix the problem without hearing the nasty noise?:doh:
I mean ,it just happens sometimes,Iīm affraid that they have to try several times turn on and off the amp until be able to hear it!

Filterlab
29-03-2008, 09:47
If you've given them the symptoms they'll be able to sort it out and will probably have a VERY good idea of what to look at first.