Scratching my head...Bluesound Node 2i direct to amp


Hello friends, long time lurker, first time poster. Earlier today, I hooked up my Bluesound Node 2i directly to my PS Audio Stellar S300 amp, just as an experiment and used it as preamp. Everything that I read would say that this would be an inferior way to listen to music to usual setup. 
My usual setup is a 2.1 system that goes like this Bluesound Node 2i<Bifrost 2<McIntosh MAC-3 (I use this as a preamp I know that it wasn't its original intention when made)<PS Audio Stellar S300 amp<Elac Carina, sub is an SVS 2000. With the Bluesound direct to the amp, the sound was cleaner, more alive, and had significantly more bottom end from the Carina's (note-when I ran the Bluesound direct, it was just as 2 channel the sub wasn't running), so much so that I was shocked when I looked over at the sub and remembered that it was off. 
So my question is this, how could this be? Is my "preamp" the weak link? I really felt like the Carina's came into their own running direct to the amp. I know that the Bifrost 2 is a better DAC than the internal DAC of the Bluesound. Only thing that I can think is that it maybe time to upgrade my pre :). Any thought's friends?

Thanks!

*Source material was a variety of MQA and CD quality tracks from Roon
128x128willg1985
I have the GCD and S300 and you can bypass by running RCA from source to analog inputs. Currently im using digitals for my node 2i and CD.
I have the GCD and S300 and you can bypass by running RCA from source to analog inputs. Currently im using digitals for my node 2i and CD.
@bilyeauxbrew How do you like your GCD as a pre? I would be only using it as a preamp and bypassing the DAC. 
Just a little update, I ended up buying a used PS Audio Stellar Gain Cell DAC for what I felt like was a reasonable price. The DAC part wasn't important to as I have a Bifrost 2. I've only had it for a few days but, you guys were right, a 2 channel preamp changed the game.

I even ran the system direct through the Bifrost just to see, using Roon as a volume control, and the GC pre added much more to the music. The Elac Carina's that I have really have come to life! 

As far as the DAC goes on the Stellar, it's really musical and has really good sound to it. But running the digital signal through the Bifrost 2 and using the analog inputs on the Stellar GC really bring it up a notch. Super clean, musical, and engaging sound. I can't stop listening. This thing is wonderful as a standalone Preamp. 

Thank you all for your help, cheers.

-Will