se a 909 and love it, I was lucky in that I bought one just before they were replaced and got a great deal on a brand new one, I often see 2nd hand ones go for more now.
It is a great amp, I find it pretty neutral, it doesn’t really draw attention to it’s self and just handles everything very well. I’d agree it is quite smooth but not overly so like many Arcam amps for example. I’ve never really pushed it and can’t wait to get some better speakers for it to drive.
I’ve used a few different ‘pre-amps’, the first couple we makeshift; a old Denon 3805 AV amp pre-outted and in ‘pure direct’ mode, it actually did an admirable job but of course wasn’t ideal. I then tried a DAC with volume pot (Beresford Caiman), it served a function but that was about it, completely flat and lifeless sound, very underwhelming and not something I’d could live with long term.
Finally I tried a valve based pre amp and this is how I have it now in a Croft Micro 25, after an initial issue with excessive gain (which the dealer modded for me) I am now delighted with the sound. It has so much drive and just feels very textured. It is a very organic sound, I’d say ‘lush’ and almost analogue sounding. The 909 is often cited as being midrange proud, this is true but adding the pre had a profound effect in bass, it is thunderous now. What I’m getting at is don’t underestimate how much impact the pre your pair it with makes. The 909 is a solid and versatile performer, it has bags of power and partnered well it will serve you admirably.