Couple of questions - are you listening in pentode or triode? What are your issues specifically with the sound? Can you offer more nuance?
Saying you don't like the PRaT and bass is sort of like saying I hate everything about the sound of this pairing. If you were happy before, are you sure you want new speakers or do you want to return that amp?
Your Q900s are easy to drive at 91dB. It is not the SPL of the speakers that is the issue. With the right amp, 15w of power is enough to make them sing. For instance, I use a 45w amp to drive speakers with an SPL of 84dB and gets loud enough to make my ears ring.
The reality is tube amps, especially in triode mode are going to tend to emphasize the mids at the expense of bass which will get a little less refined and usually treble will get slightly rolled off. PRaT typically improves with tubes at the expense of bass response.
First test would be, turn the amp off and switch from triode to pentode. Do you hear an improvement in performance in terms of bass and do you like the sound better with the exception of detail? Pentode should give the amp better control over the speakers and will tighten things up and is great for home theater. You tend to lose detail, especially in the midrange.
Second test, use your MF Pre. Attach your MF pre to the "Direct In" and see if you like the sound better. This will bypass the integrated amps preamp stage and volume control.
Third test, use the pre out on the Ayon and attach it to your MF power amp.
I suggest these tests to isolate the issue with the Ayon as this will provide a separate evaluation of the preamp and power stages of the integrated.
Use the same couple songs and listen in triode, pentode and these other two configurations. take notes and decide what you like and dislike. Then you can make a more informed decision.
Do those tests and let us know what you think?