Thanks for the answer, but that's ridiculous. Why are they doing this again? It's like the initial release of the original X7 all over again, where you were forced to have the rubbish AM1 amp.
If I could buy the Q5 without an amp and just buy an AM1 and transfer my X7ii's AM3A amp across, it would save me money. The AM3A is a great amp, but I don't want or need two!
You're not supposed to keep swapping it around, the AMP modules are not 3.5mm jacks, it is good that Q5 comes with AM03A, it ensures that it will be best for most people, most people getting it do not have X7mkii, so FiiO are ensuring the best experience for the most.
Think about it this way, I am not sure if I'd stack X7mkii with Q5, like ever, since Q5 has the same amo modules, and stacking would mean a thicker thing to carry, along with other discomforts, but I would totally stack my tablet, my smartphone, and even an entry-level DAP with Q5, making the inclusion of an AMP module excellent for me.
Think about it this way, if you have X7mkii, you most probably will not see a bump in sound quality by adding Q5, X7mkii is still the flagship from FiiO, it is in the same category as all the other ultra high end DAPs.
Q5 is not only not intended to be stacked with X7mkii due to size and concept, but X7mkii costs double the price just so you don't have to stack, you're intentionally going against the design of X7mkii if you plan to add Q5 to it.
I wouldn't bother adding any DAC / AMP to X7mkii unless it is something ultra high-end, just because X7mkii is already so amazing.
I really would love Q5 for something like when I watch and listen to music using my tablet, or for when I really need to use a more entry-level option and have it stacked.