I have not heard the Steelhead in my own system or one that I am familiar with, so I have only a general impression. I like what I heard from the systems I've heard, so it is certainly a good phonostage. I like what I run, a Viva fono, but, I have no idea how it compares in sound to the Steelhead or other phono stages for that matter.
I tend to like tube-based electronics, regardless of the potential for higher noise, poorer measurements, etc. There is a naturalness, a larger scale, and a sense of the music blooming into the space and filling the room that solid state doesn't quite achieve. I also like the way tube electronics deliver a lively, engaging sound at lower volume levels. I am also one that likes, even amongst tube gear, stuff that has more, and better, transformers. I prefer tube phono stages with a step up transformer than ones that try to achieve sufficient gain with active stages.
I can only offer some rough suggestions of brands you should at least audition for warmer sounding phono stages. There is the Audio Note (uk) line that ranges from expensive to ridiculously expensive. The thing is, their stuff does really sound good. Their gear requires a step up transformer moving coil cartridges, and they make very good transformers for that purpose. This is a company that makes most of their own parts (they wind their own transformers, make their own resistors, capacitor, inductors, even their own solder). Very much in the warmer sounding camp.
The Italian company Lector makes some good sounding tube electronics. I have heard their phono stage and I like it--a lively, engaging sound. I also liked the high end Zanden tube phono stage I heard; I believe it comes with its own built-in step up transformer (like my Viva Fono).
Have you considered keeping the Steelhead and perhaps getting something else with a completely different sound just to mix things up once in a while? That might be something easier to do than finding something that is "better" than an already fine component. I am not so inclined myself, but I have heard gear that was intriguing such that I might want to use it occasionally, even if it is not what I want to use day-in and day-out over a very long period of time. In the phono stage realm, that would be the solid state Lyra Connoisseur phono stage. I heard it in a show system that was explosively dynamic when playing records (meaning the phono stage brought a lot to this quality of the system). Unfortunately, the Lyra is no longer made and is extremely rate, and even 15 year models when they do show up are well north of $15k.
