Amplifier Help

[sHep]

When i hooked up my stereo amplifier to speakers and a record deck, the speakers emitted this low humming sound, that got louser if i turned up the volume. what could be causing this to happen? also anywhere that i could find info on how to fix it?

[mgelectronics]

If you hooked up a Turntable (Phonograph), it could be a magnetic type cartridge in it, in which case you have to connect a ground wire between the chassis of the Phono and the Amplifier. On the other hand, unplug all of the input cables. If the hum disappears, plug one device at a time until the hum reappears. That cable could have an open shield (Measure continuity from each end. On the other hand, if all cables ar out and you still have a hum, suspect filter capacitor in the power supply.

Hope this helps.

Gordon

[Guest]

sHep here.
i need some clarification with terminology.

-''connect a ground wire between the chassis of the Phono and the amp''
earth them to each other, or individually?

-''That cable could have an open shield (Measure continuity from each end''
i dont know what that means.

-''suspect filter capacitor in the power supply''
how would i fix that?


much appreciated.

[absorbentgnome]

With record decks, you have to connect a separate chassis ground wire between the record deck and the amplifier. This should remove the hum you are experiencing. The signal ground on the phono connectors is NOT the chassis ground on record decks.
You should find a small thumbwheel labelled GND on both the amp and the record deck. Connect these.

[absorbentgnome]

Apologies mgelectonics! I had not read your entire post!
No need for the same information to be repeated!

[sHep]

ah! thanks, that seems to have made all the difference. The humming stopped once i connected the earth.s.
now all i need is a head cartridge that fits the damn record deck...

thanks again!