need help badly

[natz gangoso]

mabuhay !

im an audio enthuciast frm the Philippines. i built an amplifier a week ago and it sounds good, until i found out one day that when i turn on the flourescent lamp in my room,there is a loud clicking sound coming frm the said amplifier.

is there any circuit tht can iliminate that bad sound.

pls. guys help me!

thanx a lot in advance.

[ChocoHolic]

Hi Natz!
I assume that you are running the fluorescent lamp with
a magnetic control gear.
Probably for cost reasons this might be the cheapest solution with just a choke and a starter.... This will inject a lot of noise to your power line. Do you only have issues with your amp?
Not with any radio or similar?

Well in fact, you could try to filter the noise source (line connection of the luminaire) and additional the mains line to your amp.
May be already a compensation cap for flourescent luminaires may
help... Normally these compensation caps are used in order to compensate the induktive phase shift in the current, but it will also
filter some of the injected noise. May be you can get something like this in a shop or you may find a suitable cap somewhere in the trash at an old motor ... reasonable values for first trials would range between 1µF and 4.7µF...

Of course an additional filtering of your amp may also help.
...tons of different filter topologies, which you may try.

OK, I think we should not overstress the moderators tolerance
regarding circuits which deal directly with line...

Good Luck
Markus

[ChocoHolic]

....may be also that simply your lamp tube is old...
This can also increase the injected noise.

Do you have newer tubes somewhere in the house, which you could simply exchange? If it does not work, you will not have lost money...

[kilowattski]

Is it possible to use a different power circuit? A circuit that the floresent is not connected to. This may be the most simple solution if the emissions are conducted.

[slowhands]

We need more details and facts about your amp and house wiring.

It is usually easier to stop a noise problem at the source than in the affected device. Make sure your lamp is new and working properly. Compare it with a brand new one if you can, by exchanging them.

Sometimes when an amp buzzes, it is simply a grounding problem. You may have a bad ground connection between your CD player and your amp. Check cables. Is there a safety ground connected to your amp? If so, it can be a source of noise, and you can put a small 1 ohm resistor between chassis and safety ground to see if that breaks any ground loops.

Adding capacitors across the primary and secondary sometimes quenches noise too. I typically use 0.047mf 400v film X capacitor in both positions. The cap on the primary side will filter most switch on/off noise, while the cap in the secondary filters diode noise. Hope some of these ideas work for you.