If you want to go tubes, I'd look for a hybrid tube, the Monoprice Liquid Platinum, for example.
Power isn't everything.
I would not choose that.
It still land you in mid-fi territory, in which many options to stay with for enjoyment.
I would save and skip the sea of countless (and nice) mid-fi gear.
I have a lead on a MK VIII SE for $550 that is open box with ~20hrs on it which is why I'm so determined to make it work with my setup. The oblivion doesn't have preamp out which I would like to incorporate to my speakers
If you like this amp, you can still use it. It will still push planars ok, but you will notice the meters start to dip at 3/4 volume in stock form, and to get it sounding great you will have to do some mods at least.
I keep mine as it still nice euphoric, & also a top amp when moded", but the Oblivion" is my reference "end game" currently, and can be ordered customized.
You will read in the other "Little Dot supermod" thread (link in my sig) that I was originally
not a fan of any hybrid design, until I compared the Oblivion and proved it to myself.
That one is a special hybrid.
For all the traditional tube designs,
I aknowledge the necessity of tunning of the circuits, and parts quality implementation, like in the supermod thread for the little dot amps, and so going thru all that learning, it is such a change, relief, and revelation to have an amp that does not require this (in the Oblivion).
So, if you have a great deal, go with it.
Just remember that if you want to progress to end game level with unique design & at a reachable level, I cannot suggest anything else.