Does the Transport make a significant difference

If the instrument went from middle to outside the left speaker something is, or was, seriously wrong. A proper set up system regardless of components will never misplace instruments like that. Before you spend another penny you should figure out what is or what was wrong. Calling this an improvement is misplaced.

Nothing is wrong with my system. In addition to the new DAC, I changed my digital cable, speaker cable, and went to a balanced cable from amp to preamp. The soundstage has opened up tremendously.

Unfortunately I don't have the opportunity to audition a new transport or preamp. My other thought was add a JL Audio sub for now and down the road upgrade my source or preamp. All three options are within the same price range. With the exception of my speakers, I've changed everything over the past two months. Whatever option I choose will be the last change for awhile.

11-24-14: Ricred1
My other thought was add a JL Audio sub for now and down the road upgrade my source or preamp.

Since you indicated that your P5 preamp has been sold, I assume you are envisioning the possibility of driving your power amp with the balanced outputs of the PW DAC, and the sub with its unbalanced outputs. And as is usually the case with powered subs, the input impedance of the unbalanced line-level inputs of the JL subs is low, e.g., 10K for many or all of them, and IIRC most of them do not provide speaker level inputs.

Given that, before purchasing a sub I would suggest asking PS Audio if the balanced and unbalanced outputs of the DAC are independently buffered (i.e., driven from separate output stages). If they are not, adding the sub could very conceivably have adverse effects on the sonics you hear from your main speakers.

Regards,
-- Al

The deal fell through and I still have my preamp.