"Zen" tube phono-amps ?

The problem you'll find in seeking a 'Zen' phono stage is that phono stages inherently need a lot of gain. That implies more than one stage. The RIAA eq is then going to chew up even more; insertion losses on passive RIAA sections typically run to 20 dB or so. (I'm quoting from memory, but I think that's right.)
If you find such a beast, be sure and post...I'd like to build one just to hear how it sounds.