OK, so I don't need a SUT 😁!
@lewm @jasonbourne71 Of the three gain levels on the Stellar, my system sounds best at the lower setting, which is the recommended setting for the LOMC Cadenza Black. The other two don't sound as smooth. I've also used Stellar's custom loading option set at 30Hz, but finally settled on 60Hz.
@mashif I'm going to try the all RCA route, which should reduce the DSD output a bit. I've been playing the DAC at 90% volume level for years. If necessary, I'll futz with that some more to get the two a little closer together.
Regarding LTA, you are correct. I live about 45 minutes from their office. It's always a pleasure going their - everyone is very nice, very accommodating, and fun to be around. Nicholas has been very accommodating, allowing me to home audition their preamps and power amps. I'm looking to audition their new DAC soon.
Thanks everyone for your help!