Mixing or matching component brands

I've been into audio gear since I was probably 14 years old.   Started out with whatever I could afford. Eventually, I moved up to Yamaha separates in the mid 80s. Amp, preamp, and tuner.  Pretty nice, really.  I started reading Stereophile, so I wanted the highest rated gear that I could afford. That was an Adcom GFA555 amp and NAD 1300 preamp.  Then, I decided to try a conrad-johnson tube preamp (PV-14L) and a Coda amplifier.  That was their strong suit, I think.  I wanted to stay with a tube preamp and solid state amp, so I upgraded to a better Coda amp and a Linear Tube Audio MicroZOTL preamp.  The pair works well together. 

I’ve always mixed components. My first system I had Rotel amp and pre. Cd player and obviously speakers were different. Had that for 23 years with no troubles at all. The last 4 years I’ve had an Aric Audio amp and pre, but different dac, streamer and speakers. Now, I have different amp, dac, streamer and speakers. Good thing about current system is I got hear the components all together before purchasing. Had good synergy so that took the guess work out of it. 

I enjoy my Hegel H390's onboard AKM DAC but would like better separation and Soundstage depth. Adding Hegel's D50 standalone DAC seemed like a no-brainer but in practice, did not work out. While it did yield these benefits, I found it utterly unengaging in terms of emotional connection. Whether due to the D50's ESS chipset or a change in the company's sonic goals, the two DACs did not, to my ears, appear to share a common "house sound". 

So, be careful making assumptions.

Thanks to all for sharing your insights and experience. Seems that auditioning a system, whether mixed or matched, would be particularly valuable in making this decision.

Ultimately, absolutely.

One of the things it's most important is to audition and listen to the music not the system. Figure out if it's emotionally connecting to you or you're just hearing incredible quantities of detail. There was nothing wrong with detail and slam, buty ou want something that emotionally moves you .That's actually why most of us listen to music.