Phono Stage - The great analog tragedy

What Dover said.  I can give you some "obvious" advantages of a full function preamplifier vs separate line and phono stages. Provided you allow for the luxury of an outboard PS for the full function preamp, I would argue that is the inherently superior configuration, all other things being equal of course.

I can think of a few great preamps from the "golden era" with good phono stages, including the Marantz Consolettes (never heard them with the "bridge") and the tube 7 (often called a 7C but the C was for the cabinet). The ARC SP3-a-1 was great in its day and there is apparently an update for it. I ran an ARC SP-10mkii for years- great sounding, but it was very microphonic.

I think the trend toward "separates" probably coincided with the advent of digital front ends- why pay for a phono stage if you don't need it? And there was a period where there were not as many phono stages marketed as there are now. I remember when I was setting up the system I have now- and trying to hunt down an Expressive Technologies step up to use for the SP-10. Pretty scarce in the wild. 

I wound up going the line stage-phono stage route. I requires an extra piece of interconnect, which is a potential downside. On the upside, I roll the power supply tube in the phono stage, which makes a huge difference in the overall voicing of the system. 

@dover your list of vintage standalone phonostage is very interesting. I will check them out one by one.

Having a phonostage inside a preamp or outboard is notional. A preamp with phono and external PSU is probably the best thing. Where I was coming from was, there was no cutting edge work going on in phono, like it was happening for amps, preamps, CD players and Turntables. In the 60s we got Marantz, Mcintosh, Quad for tube amps. In the 70s came in ARC, Naim, followed by Mark Levinson Class A, Krell Class A etc. Then there were Japanese giants like Sansui, Pioneer, Yamaha building the best of the seperates. Take any phonostage (other than the Marantz 7 which I have heard great things about) built inside these components, they cannot be considered in the same league as the remaining of the amplification chain. No cutting edge work on phono. They sound noisy and midfi.

I think your experience must be limited, and I disagree with your premise. Not to say those vintage units were better than what we have now, but only to say you might be surprised at the similarities between old and new circuit designs. We simply have better parts today and the benefit of hindsight. For one example, the Marantz 7C originally used selenium rectifiers, because that’s what they had available. If you simply upgrade the rectification, the SQ takes a leap forward. 

The Sansui AU III is a commonly listened to by myself as an Amp used for driving Stacked Quads.

If I can say it has one advantage in comparisons to other same models that might have been heard by others. Which is where it has been fully overhauled where Components are concerned and Tube Rolled for across many Years. With the permutation for Tubes in use, it makes the option to Bi Amp with the spare AU III quite an expensive consideration.

The Phonostage on the AU III Model has been heard on different occasions with a range of SUT's or Head Amp's in front of it. Where during these occasions as a device for replaying LP's, it has proved as impressive a the Modern Day Design Phon's that have been loaned for use at the same arranged session.

Very experienced individuals with audio equipment, as a result of their listening to the Vintage Phon' have found criticism, only good appraisal has been shared.