Bluesound node 2i DAC VS Vincent SA-T7 DAC

Got a question for you DAC experts. I’ve been running the bluesound node 2i for about a year now and I’ve been really pleased with it. The software could be better but for $550 I thinks it’s hard to beat. Fast forward to about 4 months ago when I added the Vincent SA-T7, their flagship preamp. I had been using the RCA connectors but today decided to try the toslink connection. Ok so the bluesound’s dac’s sampling rates are 32-192khz. The Vincent’s are  24-192khz. Am I correct that a higher sampling rate would be the better DAC? Is the rate changed once it goes through the Vincent? I left the rca’s in place so I can toggle between the two for comparison. I don’t know if it’s placebo or not but to my ears the toslink is better. It definitely is louder than the rca’s. I’d like your opinions on this and thank you in advance.