Upgrade Question

I'm looking for suggestions on what you think would have the best bang for the buck for my next upgrade. Current system consists of ARC ss 100.2 amp and LS15 pre, B&W 802 matrix III, Linn Ikemi and modest cables (Tara Ref Gen ICs and Audiodyne silver speaker cable). I'm due for new tubes in the preamp, so changing from the original tubes can also be thrown into the mix. Upgrading from the Rega Planet to the Ikemi was huge and I'm looking for a similar impact on my next move. Thanks.