Best Full-Function Preamplifier

I second @mulveling’s rec for a used VAC. The higher-end models have excellent phone stages using 6 x 12ax7 tubes. As for Lundahl transformers, many people find them a feature, not a bug, although they can certainly be bettered by some separate SUTs.

I’ve been running a Phi Beta preamp for 12 years with dual MC phono. Built for longevity as well as great sound, it goes all day like a lumberjack, usually for 12 hours each day, since I work at home. The phono, while not quite as refined as my Allnic H3000, is robust, natural, tonally rich and throws a massive soundstage. I could easily live with it as my only phono if I cut down to just two tonearms active (from 5). I also have a Modwright PH9.0 that I never use because the internal VAC is better IMO. The Phi Beta, TOL in 2011, has been superseded by models including the 2a Signature, Master, and Statement, which employ a very similar circuit but are no doubt even better. Great stuff.

@wrm57 

I have a good friend with a Phi Beta, recently refreshed by VAC with new 6-tube phono - I think it's the Master phono board! It's a fantastic, top-class VAC, and definitely one to look out for on the used market. It clobbered the Ren V haha. 

@mulveling , yes, Kevin got this phono circuit right. Mine is also kind of a one-off now, having been upgraded with Statement transformers (pre and phono), and slide-in screw terminals on both MCs that let me swap in any value of transistor for loading. I use nude Vishays. Brent did it for me. Those guys can do anything!

I seriously disagree with those who suggest one is best off with separate phono and linestages.  (And by the way, the term "preamplifier" historically assumed a linestage and phono stage on one chassis.)  Here are the advantages of an all in one unit: (1) The signal runs through one fewer pair of inputs and outputs and one fewer (often very expensive and always SQ affeccting) IC is required.  This point alone is nothing to toss aside as not only do ICs add flavoring, at best, but also the connectors are a source of subtle alterations in SQ. (2) Just because the phono and linestages are on one chassis does not necessarily mandate a single power supply.  The best all in one units have a massive power supply on a separate chassis and often that box incorporates separate supplies for phono and linestage, respectively, and (3) having the phono and linestage on one chassis also gets rid of an output coupling stage entirely or at least permits the use of a much lower value capacitor in a capacitor coupling between phono and linestage.  Also, in a tube unit, no need for a cathode-follower at the output or and a solid state unit, no need for the analogous solid state topology.  As for separates, one advantage (to the manufacturers) is cost.  If you really want to spend money and pay for the same thing twice (chassis's and PSs), go for it.

I own both an Atma-sphere MP1 (albeit a fairly ancient one with some updates) and an Essential 3160.  Both of these units are fully balanced, inputs to output, and both have outboard PSs with separate supplies for the phono and linestages.  I can only imagine the sound of an up to date MP1, but it is somewhat restricted with only one pair of balanced phono inputs, designed for high gain but can be reconfigured for low gain.  For flexibility and amazing transparency, I would highly recommend the 3160 or the latest greatest iteration, the 3180, which I have not heard, in that both of these have entirely separate circuits for MM vs MC cartridges.  My 3160 has an exceptionally lucid linestage which was a hard sell to me, because I am at heart a tube guy.  I can only imagine how great the 3180 is going to be.

@lewm you bring up many very good points regarding SQ that should be considered when looking at full function vs. separate line and phono stages.  I went through several iterations of “separates“ before finally settling on a full function preamp for spinning records.  Why, because for the same dollars it just sounded better.  I have since decided, primarily because I’m old and lazy, to go with strictly a digital source. Particularity when considering the OP’s budget (if you have enough money in this hobby you can pretty much do anything) looking at a full function preamp like Vac or Atma-Sphere or I’m sure there are a couple of others that don’t come to mind, will give him the biggest bang for his bucks in his quest for SOTA.