Suggestions for Path Upward?

I am interested in continuing to improve the sound of my system.

Currently I have 2 Bel Canto EvO200.2 monblocks connected to a Subfire Theater Grand with MIT 350 single ended IC's driving a pair of Audio Physic Libras connected with Transparent Ultra XLs. The front end is a Sony 333ES changer connected to the Sunfire with transparent Ultra single end IC (analog for SACD) and Kimber Select 2020 digital cable.

I listen primarily to Jazz, Blugrass, and vocals. I am reasonably happy with the sound, but I have a nagging feeling that I'm just an upgrade away from something great. I'm thinking I should either upgrade or mod the Sony or get a preamp with an HT loop.

Where should I go from here?
The only piece we own concurrently is the 333ES changer for which I added in a stock ART DI/O (with Bolder cables) which enhanced redbook presentation over the internal dac in the SONY. You can get one for about $140 with I believe a return policy. Cheap audition, just remove the tube as it draws power and is not necessary with the d > a side anyways. Not sure if it will outperform the Sunfire as I have never heard that unit...