The system sounds fantastic, however I believe it could sound even better with modern components.Indeed. I will throw an idea in another direction. The SF SFL-2 is 25 years old. I had this for a short time and found it to be very flat and dry for a line stage loaded with tubes.
Tube line stages have come a long long way since then. Updating this system link by throwing another $3-4k into a "newer" line stage would likely take your system to levels far beyond changing the digital source.