Whatever amp you planning to buy, a good DAC and digital sources is paramount IMO. A good amp is “only” amplifying the signal coming from the DAC/TT. If the audio signal coming from the DAC isn’t good to begin with no amp can ever fix it. I consider its best to start with as good source as possible, no matter if you use a turn table or a digital player.
I have not heard the Master 11 + Singxer SU-1 myself, but if its sounds like a combination of Master 7 and Master 9 + Offramp 5 it might be worth to put on your list. This solutions cost more than just a Master 9, but also is more of a complete solution which can be used both for the HE-6 and active speakers.
Btw, my Marantz PM 11 is an integrated speaker amp so I don’t use Master 9 as a pre amp.
Yes, I agree. Good source is of major importance and my priority at the present time. However I prefer to purchase a really good network player (like e.g. Lumin) instead of buying separate DAC as I think its more convenient and beneficial for sound quality ( as you reduce jitter by bypassing PC in the audio chain). I would like to have Lumin and M9 in my audio chain. Hope its going to happen in a year , touch wood.