Stereo Power Amplifier - issues - Plz help

[magma]

technically any ckt creates noise
a badly designed power amp creates its own noice too

but it really has to be badly designed or badly executred to hear that hiss at listening position

another possibility is DC
theres no way of checking that though except putting a DC blocker

rgds
ALi

 

[Kannan]

Is it a hiss or a hum...
The amplifier (transformer) hum that does not increase with volume and varies with time of the day is usually DC offset and associated mostly with toroidal transformers. There is little you can do about it.
if it is a hiss, it probably or most likely is a ground loop issue.
First get your electrical ground corrected for the whole house...not only for stereo it can be life threatening when operating equipment like mixie and washing machine.

 

[elangoas]

Observed something today..

When the fan regulator is set to full in the living room, there is faint hiss from the listening position...

When the fan speed is reduced on the regulator, the hiss gets little louder...

 

[Audiodoc]

You can easily test if grounding will help by temporarily connecting the ground pin of a three pin socket to a tap of your house which is connected to the underground water supply of your house if you are using galvanized pipes. If this helps then you can get your electrician to properly ground the wiring.

 

[magma]

one of your neutral wires ( or should i say what was meant to be the neutral ) is either wrongly connected or leaking into the ground pin

some dumbass electrician used this shortcut because he didnt wanna use 3 core cables everywhere

i unfortunately have been through this in one installation

As doc says
first see if a pure 3 core wire from the mains into the distribution box sorts this problem out
if it does no need to do kharcha or magajmari of buying additional equipment or overhauling your entire house electricals

if the above does not work
2 possibilities
BAD power amp
or DC in the line

 

[elangoas]

Many thanks for the detailed inputs.. Really helps narrow down the issue..

Have called for a certified electrician this weekend, will update once he is able to trace & fix the issue..

 

[greenhorn]

another possibility - some of the input transistors might have started becoming noisy - how old is your amp?

 

[elangoas]

another possibility - some of the input transistors might have started becoming noisy - how old is your amp?

About 7 - 8 yrs

I did call the local electrician to check on the leakage, but he wasn't sure of it.. He diverted the topic to grounding not done.. I wasn't very sure of what it is, hence requested for FM help for any pointers..

 

[keith_correa]

I just think the electrical issues should be sorted out by someone local - it's life threatening, after all. After the electrical issues are sorted out, THEN let's get on to other stuff.

I did call the local electrician to check on the leakage

What leakage?

 

[elangoas]

What leakage?

When a switch is turned on/off, there is a disturbance in speakers..Hence termed it leakage...

 

[elangoas]

Update : Grounding is now complete... I have disconnected the speakers and power-amplifier for now.. In the process of swapping some hi-fi components..So yet to check if the issue reported earlier still persists.. Will update on that in sometime..

But still observe some electrical issue..

When watching television, when any switch is turned on/off. the TV flashes for a second as if it lost DTH signal.. I observed this yesterday..

But i didn't see that happening today..

Any insights on this issue?