Help me resolve humming noise problem

[gobble]

Thanks for all the replies guys.

No other power transformers close by. The power cables and RCA's and speaker cables criss cross a little at one or two places max. There is a RF tower at about 40 meters away at same height as my terrace.

Viren is sending me a pair of shielded ICs. Lets see how it goes.

With all the cell phone radiation I think I need the aluminum foil wrap more than my equipment. Maybe I will stitch dresses made of these aluminum food wraps.

Does it really shield from RF effectively?

Regards

 

[Hiten]

With all the cell phone radiation I think I need the aluminum foil wrap more than my equipment. Maybe I will stitch dresses made of these aluminum food wraps.

If you do Please Please Please Dont go outdoors in the harsh sun

 

[Sumit]

Does it really shield from RF effectively?

Regards

Use it and find out. As I said earlier, it might work. Not sure.
Its only a suggestion. Won't cost you more than fifty rupees of Aluminum foil.
What you gotta lose??

Cheers!

 

[dinyaar]

Thanks for all the replies guys.

No other power transformers close by. The power cables and RCA's and speaker cables criss cross a little at one or two places max. There is a RF tower at about 40 meters away at same height as my terrace.

Viren is sending me a pair of shielded ICs. Lets see how it goes.

With all the cell phone radiation I think I need the aluminum foil wrap more than my equipment. Maybe I will stitch dresses made of these aluminum food wraps.

Does it really shield from RF effectively?

Regards

Well in theory it can act as a screen. Try it.
When components share common ground this 50/60 hz hum problem can occur. Ask an electrician to open the wall outlet and check if polarity is correct and if ground is good.

 

[gobble]

Well in theory it can act as a screen. Try it.
When components share common ground this 50/60 hz hum problem can occur. Ask an electrician to open the wall outlet and check if polarity is correct and if ground is good.

What polarity? Sorry I'm lost here.

Regards

 

[stevieboy]

gobble,

i think viren forgot to program your preamp with words that's why the poor thing hums, don't blame it!

seriously though only two probable solutions.

1. attach a thin grounding wire from the rear ground terminal in the preamp to under the screw on the front plate of the preamp

2. try different tubes. my phonostage had a hum problem with the stock tubes umm forget the names/number... hummmm... these had lower gain, the 12 AX7s have 30% more gain and using them the hum disappeared. note, its not about changing brands its about changing tube types that are equivalent subsitutes to the ones currently in the amp. can check with viren on this or research.

the ground wire ought to reduce the hum to a not so irritating level with music on.

regards

 

[stevieboy]

Hello gobble,
are you getting the hum from speakers or from the prem amp itself. when I turn on my amplifier there is a slight noise from the tubes as if they are being heated. I do get some humming noise from the speakers when listening to TT but that is not very significant.
thanks.

hi mahiruha,

i think that's the sound from the caps in the amp and not the tubes. the sound disappears or is lower after a few seconds.

regards

 

[daddycool]

Try this.
disconnect your RCA cable between amp and pre at the pre end. Now as per your original post, there should be no hum. Now with power to all 3 turned on, carefully touch the outer conductor of the RCA plug to the outer of the RCA socket at the pre. If the hum comes, it confirms the ground loop.
Shielding will not help in that case.
Caution: Repeat Dinyaar's warning. Take care that the inner conductor of the RCA plug does not touch anything, most of all your finger or you might blow your speakers.

 

[gobble]

gobble,

i think viren forgot to program your preamp with words that's why the poor thing hums, don't blame it!

seriously though only two probable solutions.

1. attach a thin grounding wire from the rear ground terminal in the preamp to under the screw on the front plate of the preamp

2. try different tubes. my phonostage had a hum problem with the stock tubes umm forget the names/number... hummmm... these had lower gain, the 12 AX7s have 30% more gain and using them the hum disappeared. note, its not about changing brands its about changing tube types that are equivalent subsitutes to the ones currently in the amp. can check with viren on this or research.

the ground wire ought to reduce the hum to a not so irritating level with music on.

regards

Thanks. I may have tried item 1 already, dont remember but i will try again.

Changing tubes isn't an option yet at least not during the audition stage.

Hopefully this will be resolved by Saturday with Viren's cables. In the meanwhile I've been humming (pardon the pun) a new song I composed in the last few days ...

(Sing to the tune of Dum Marro Dum)

Hum maare Hummmmmmmm :licklips:
Maike jaye Hummmmmmmm :indifferent14:
Bolo subah shyaaaaaaaaam hyeah:
Humming Preamp humming Amp!

:yahoo:
Cheers

 

[mahiruha]

hi mahiruha,

i think that's the sound from the caps in the amp and not the tubes. the sound disappears or is lower after a few seconds.

regards

Hello Steven,
well the sound stays. But it is not much of an issue since I am far away from the amp while listening. Is your amp absolutely quite while in operation. I mean to say the sound you hear when you turn on the tubes does it stays or dissapear. In my case it stays.
Thanks.