I started out with a Shunyata Diamondback which was very clean but lacked low end. Recently I tried a Chris Venhaus Flavor 4 and it made all the difference. Improved weight in the low end, more palpable midrange and more sparkle in the highs. Better overall focus. Highly recommended and affordable. I also swithced from Chimera Advantage II ic's to Vampirewire CC II's. If you're not familar with the raves about the Flavor 4,(and I'd be surprised if you weren't)check the Cable Forum at Audioasylum. Many members, including me, think it's a great cable--and it's reasonably priced as audiophile aftermarket pc's go. For tubes, I've found better top to bottom performace with RCA NOS (I think they're very solid performers). BTW, I used to complain about a lack of low end with the Jolida, but since I hooked up the Flavor 4 it's been beating my Simaudion Nova in the low end. BTW, good move to purchase the stock unit. I ordered my unit from Underwood Hi Fi with the Level One upgrade. I've never been thoroughly convinced it was worth it, but maybe I felt that way because I was using the wrong PC on the player. Just add some vibration deadening material to the underside of the cover, tube roll and add a good pc and you'll be tapping your feet.