If you get an opportunity to audition a tube or hybrid amp, it may be wise to do so. It can be very difficult to picture the sound without hearing it. The primary difference in tubes is the addition of second order harmonic distortion, which can be euphonically pleasing. By nature of being analog, they can also accent or smooth the mids, they can reduce treble, and generally "warm the signature", but that can depend on the tubes. Tube amps, and especially hybrids can still be exceptionally clear. SS is more "stark" in presentation. It has sharp detail and fast transients. Tubes/hybrids will adjust that a little, but for many it is still highly detailed with more of an organic tone. Tube pending.
If you want a purely neutral SS amp in all its analytical glory, and don't mind dealing with 1/8" jacks and a mid-tier volume pot, a JDS assembled O2 would set you back a whopping $150 or so and would give you all the SS neutrality you could dream off. If you want even more perfect analytical glory, you could go big with something meant for studio use like SPL gear (Phonitor, Auditor.) If you want to go mid-way, $1k-1.6k, a Benchmark DAC1 will give you a pretty much top-tier neutral DAC and a headphone amp approximately the same or slightly better than the O2.
If you want something not flat and neutral, then you can look into exotics, colored equipment, and things with tubes. Tubes are more expensive over the long haul because you get into tube purchases, and if you really like it exotic, as I'm learning, some of that stuff costs some serious money for a consumable item. But even the cheap stuff can be pleasing.
My advice would be, if you've got $1k to play with for an amp, either dump it on a DAC1 and be done with it, you'll have something you know measures well in both areas. If you want to experiment, buy an O2. It's cheap and gives you a taste of neutral. From there you can choose your direction based on desired coloration.
I've read about how the DAC1 is just old news, like something like the Lavry DA11 or something was its replacement or something like that, but I'll look into it. How good can an amp be for $150? Is it simply the lower production cost (DIY) etc. or is it just a mediocre quality amp? I'm aware of the rule about discussing "it" so I'll post and research "it" elsewhere but I'll look around on here too. Or is that rule gone? We can take it to PM..