Rumbling ?

When I lower my needle in the grooves music is first to appears....soon to be accompagned (from the first second or some other lime a little later) with a steady rumbling low frquency sound that has my powered subwoofer going wild........all stop the moment I remove the needle from the record.
It did go away a couple of days ago for a while after I had played a bit with the arm's various adjustments
but it is back again.
Any recommendations ?
You need to better isolate the table. It sounds like you are getting a little low frequency feedback. This is why some preamps had a filter to roll off the bass below 20hz.
I've also found you could lower the dustcover down while playing and this will stop it sometimes.
Dear Pboutin: Which TT/tonearm/cartridge do you use? and what level/volume happen that? with all kind of music/with all LPs ?

Please give us some info about .

Regards and enjoy the music.
I had the same symptoms. My problem was low frequency feedback. The final solution for me was using 30 foot long interconnects between the phono pre-amp & pre-amp, which allowed me to move the turn table well away from my speakers. Playing with arm setup & platform weighting & floor mass loading etc. would effect the problem & may be good enough to fix the problem in your case. Others have had great luck with wall mounts for the table. If you think you are getting feedback through the floor you should be able to verify this by pushing down on the table with your thumbs, this should reduce the rumble (but it ain't a comfortable way to enjoy the listening experience). Good luck!
You may want to do a simple test to see if Bigtee's suggestion, and it is a good one at that, that acoustic feedback may be the issue. Lower the stylus into the groove with the motor off and the platter NOT spinning. Advance the volume a little bit above your normal listening level and lightly tap the shelf that the table sits on. If the rumbling starts, it will rapidly increase in level. This is acoustic feedback. Turn the volume down immediately. You will need to better isolate the turntable. Check the archives here, there are many possible solutions.
Reading Bigte I decided to move my little P25 well away from the subwoofer closer to my permanent table where the Rega had also been used in the past..........the rumbling have not reappeared's a good start for now,......thanks very much you guys.