Bass distortion-Playing LP's only,,,,please help


VPI Prime----Ortofon Black Quintet (low output moving coil cart)-----Plinius Koru Phono Pre( loading at 20 ohms/gain at 66 db)-----Parasound Halo Integrated -----Martin Logan Montis speakers which have powered bass cabinets.

Using any other source component I have absolutely no issues. When I play an LP and increase the volume past 10 O'clock which is a little loud....but not ridiculously loud-I at times get this huge wave of bass distortion. I do have bass controls on the Montis's...and I have turned them down into the negative, but I still get what I previously described occasionally. 

Any and all help would be appreciated. This doesn't always happen, but its frequent enough to drive me crazy.

Thanks in advance.

krelldog

Showing 1 response by cerrot

I would look at my tonearm alignment.  If the VTA is off, you'll get overwhelming bass.  Assuming you have a VPI unipoint arm, they are very good, but very difficult to set up.  Look at the arm as you track a record and see how it looks.  Make sure the azimuth is set correctly, the stylus is 90 degrees in the groove (cartridge isn't 'listing' to one side).  Look at the base of the tonearm and make sure that is balanced perfectly and not listing as well.   It should appear as its floating, not dragging.