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 owned a Mac surround amp and pre-amp for years. It never sounded that good with two channel. When I did finally switch to pure two-channel, it was an amazing difference. In my experience, I agree with the others, replace the Mac.


Man, love to hear someone that owned it as well say this. Now the fun begins! Thanks @deadhead1000!


Contrary to a lot of thoughts the preamplifier is the most critical source component a great one can make a system and a so so or bad one can cripple a system so yes find a preamp that does not change or alter the bluesound and if your lucky find one that enhances it and yes macintosh components are not the most transparent of components they are a perfect example of listen to our sound not accurate sound.
Maybe it is just me, but it seems all the home theater receivers I have owned, four so far,  sound fine in home theater with movies but fall short of a good quality two channel sound system.   Even putting them in "Direct" or "Pure two channel" mode, sounds even worse.   Am I the only one hearing this?  
Thanks for all the replies. Any suggestions on pre's that would match well with the PS Audio S300? I'm want to run it 2.1 with an external DAC. I was checking out the Stellar Gain Cell but I don't think you can bypass the internal DAC. Budget $1500ish, open to new or used. 
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.