Upgrade from Ayre QB9 DAC

Have you considered a PS Audio Direct Stream or Direct Stream Junior?

I own the Ayre QB9 DSD and a DSJ.  I use the Ayre QB9 as my dedicated headphone DAC.  I have A/B’ed them, DSJ was more revealing in the midrange and upper frequencies.  Little bit better defined lower end, as well.  I have nothing but good things to say about the DSJ and PS Audio.  

They do firmware updates periodically, which you can alternate between them for different sound profiles, depending on which one you prefer.  

The Ayre Codex DAC is in current production while the Ayre QB-9 DSD DAC is not. 

The sound quality of my Codex DAC is excellent and I suggest you give it listen.  I have used my Codex DAC as a DAC and its sound quality was excellent.  In addition, I also have used the Codex DAC as a pre-amp with great results.   I am currently using my Ayre Codex DAC in my 2 channel home theatre system with the Ayre AX-7e integrated amplifier.  

Several years ago I had the Ayre QB-9 DSD DAC and believe the Ayre Codex DAC sounds better but, of course, everyone has a different opinion on this.  I suggest you audition the Ayre Codex DAC.  

My Codex sounds better than my QB-9, IMO

I I love my Bryston DAC 3, but it doesn’t do MQA