Another thing to consider if you’re using the DAC in the Node would be to upgrade your DAC and digital cable. The newer R2R DACs tend to have a more natural and organic sound that may yield the improvements you’re looking for
This is an excellent recommendation. No doubt that going from the B and W to Zu speakers is a pretty different direction. However, I strongly suspect that the Node DAC is a weak link bottleneck hindering the current sound quality. Certainly worthy of consideration. I also agree that a high quality digital cable makes a notable difference.
Charles