Solved! Thanks to suggestions from WaynerN and mprince on AK, I simply moved the adapter as far away as possible and plugged into a separate outlet. No more pulsing! I don't think this was a TT interaction because the XPS-1 would pulse even with TT unplugged.
I can report plenty of gain with the XPS-1 (in my MM TT) - my Raven Audio Blackhawk is at 9 o'clock position, about 2.5 and gain is about the same as my digital source (NAD M51 which I keep at 0dB). The XPS-1/Blackhawk is clear and quiet. I'm happy with the combination. Now, on with the TT upgrade research after 27 years.... :^)
I can report plenty of gain with the XPS-1 (in my MM TT) - my Raven Audio Blackhawk is at 9 o'clock position, about 2.5 and gain is about the same as my digital source (NAD M51 which I keep at 0dB). The XPS-1/Blackhawk is clear and quiet. I'm happy with the combination. Now, on with the TT upgrade research after 27 years.... :^)