I was having a similar problem. I have been using a Grado Reference Sonata with my Rega RB300 Origin Modified arm on a Sota Star Saphire table with the Sota Reflex clamp. I sent my arm to an Audiogoner (Michael Wharton - teatime66@hotmail.com) for rewiring the arm in Cardas and installing a Cardas 5 pin DIN termination. I purchased a custom tonearm cable from a terrific fellow in China that incorporates twisted pair construction of LC-OFC wiring with braided copper shielding, hermetically sealed insulation and an RF stopper - all for a very fair price and QUICK turnaround). The problem is completely resolved. I am hearing much deeper into the vinyl now even before any meaningful time for burn-in has occurred. I could not be more pleased. Actually, this is one time I can be the guy to say that he cannot believe the magnitude of improvement a tweek made.