Change my AA front-end

I'm suspecting my AA digital gear may not be providing ALL the bass energy possible IMS. My buddie has the same Sonatina speakers and even on 6" granite platforms has better bass response. Of course, his room is smaller, but I believe his Theta transport and EVS dac are just that much better in the bottom-end. My gear> AA dds.pro transport / dtipro.32 (ad.3 ditter) jitter filter / ddev3.0 dac with Dusty Vawter's mod and Perpetual Technology op-amp upgrade / M.P.S. dedicated power supply for dde-dti. I'm using Audio Magic i2s mystic reference silver throughout. BMI Whale Elite power cords on dds.pro & M.P.S.

Not having sampled any other CDPs lately I'm interested in recommendations for a CDP (new or used) that would improve apon the AA gear and be purchased for what the AA could be sold for. I don't want to get into seperates or put anything into the upgrade. SACD is not an important consideration. I'm using a Moth s45 SET integrated amp with the Sonatinas and Shunyata Hydra PLC. The only areas I want to improve are bass weight and overall fullness to the presentation. I'm also looking into adding a tube preamp down the road. Thanks.