Best Full-Function Preamplifier

Essential, Accuphase, Atmashpere, all good choices, great choices actually. 

I would advise you to look at the Supratek web site. I have what some would consider pretty close to a reference rig and use a Supratek preamp. 

If you need all in one...

Save some money and look for a Doshi V2.1 or an Audio Note M5 phono.

Separate units you can go Coincident Technology.  If you need a remote then a top tier unit may be out of the question.

EAR 912 is excellent. Seconded observation (possibly in my future). Very  spacious, open sound and excellent phono stage. Not too many tubes (Atmosphere using 16 tubes, mid-spec Mullard AT7s-that’s expensive and how many hours do they last in it, in an EAR 912-10,000 hours probably, very long time).

@dentdog May I ask which Supratek preamp you are using and which amp you have mated it with? I am waiting on my Supratek Grange Signature to be built currently...

Like I said...