I'm getting very little noise indeed from the motor, belt or stepped pulley, but the idler itself makes some noise on it's bearing - I'm basing this on running with the platter off. It is noticeably quieter running if you hold the idler away from the step-pulley. I'm waiting for my order to arrive from Schopper (motor grommets, belt, capacitor) before finally rebuilding it, so I've no idea about stability / start up time yet. I think I've done a decent job with rebuilding the motor, it is certainly no noisier than either the Lenco or 301, so I assume I'm in the ballpark. It also runs cooler than both of those.
Tony.
PS on yours how much noise translates to rumble? That's the only thing that matters, i.e. what comes out of the speakers. Have you got the iron or alloy platter?