If you're dead-set on using a Rega arm on an LP-12, I would humbly suggest the Origin Live modified RB-250 in lieu of a stock RB-300. Check out the website at www.originlive.com for details. Some of our other members are using this arm with great success. In general, Rega arms with the structural modification fare better on the LP-12, with its "older-style" sprung suspension/isolation system. Regards, John