Hum question


When I engage the start platter button and play an Lp...hum is minimal...however when I stop the platter...it becomes quite aggressive...not using a Grado cart...simple budget phono staged no adjustments...any thoughts?...stage too close to turntable?
phasecorrect
What table are we talking about? is it grounded? where is it plugged in?
are you sure hum is minimal while record playing ? or is it just covered by music and mixed to it ?
if you have a hum, you won't really hear what you could hear.
I've been struggling with hum for a long time (it's a long story): war is not over yet but when I win a battle I find out a new world...
and yes, when I lower the tonearm on the record I cannot hear (or better: distinguish) hum anymore.
HAVE YOU TRIED REVERSING PLUGS?? 180 DEGREES. just one at a time... YOU MIGHT HAVE TO USE A CHEATER...BUT IF YOU DO FIND THE HUM...REWIRE THE PLUG AND DUMP THE CHEATER. JUST BE INTERESTED IN REMOVING THE HUM WITH THE CHEATER.
@Stringreen: would you please tell me more about this procedure ? I mean: would you please explain it with different words ? I'm italian and English is not my mother tongue so I must admit I didn't understand what you suggest, but I'm very interested in every possibile means to get rid of hums...
what I don't understand is:
- what do you mean by 'reversing the plugs' 180 degrees ? does this involve disassembling the interconnect cables or what ?
- what's a cheater ?
thank you very much in advance
Sorry Daneile, I will try to explain it further. In the US, our electrical outlets have two wide recesses and usually one pin-like recess which accomodates the male plug from your component. In more modern connections, one of the wide recesses is a bit larger than the other. My suggestion is to unplug your component (one at a time) and turn the plug 180 degrees so you are now inserting the plug "upside down". Because the long pin is now not in its proper position to allow the plug to be inserted into the wall, You can go to a hardware store and buy an adapter with only 2 wide prongs and with no long pin. Be sure to get an adapter (cheater) that is able to accomodate the slightly wider main pin ,,,these 2 main pins may be of slightly different widths. If you can't find this kind of adapter, you can simply cut off that long round pin. You very well might find that the hum is gone with the plug reversed in the wall. If that is the case, you can replace the plug wiring it backwards, or cut off the ground connection (the long round pin). I found many ground loops this way. Good luck....let me know if this solves your problem. One more thing...these adapters will slightly degrade the ultimate performance of that component, so you will just us it for testing.
ah, ok, Stringreen, now I undesrtand.
and I must say that I already made that attempt (exactly the way you describe it, except that it's eaasier with italian plugs, which have equal prongs), unfortunately without success.
thanks anyway, ciao.
OK Daniele...now what I would do is plug the phono into a high level input of the preamp which eliminates the phono circuit..testing it this way, make sure the volume is way down and slowly bring it up to see if the hum is present there.
OK, I'll try :)