As a longtime user of vintage gear which has provided excellent performance and musicality, I can say that in the last few years, new components show big improvements in signal-to-noise ratio, linearity of op-amps, and the emergence of variable gain stages. A lot of the budget high end gear today has the transparency, bandwidth, s/n ratio, current delivery, frequency extension, speed, AND musicality previously associated only with the really expensive gear.
For examples:
The new Benchmark DAC Pre is highly regarded in all circles. Its line stage is considered to be excellent. Yet the only type that could fit in such a small chassis is an op amp. A few years ago op amps were widely reviled; now they're becoming main stream high end.
My 2004 Outlaw 950 multichannel pre/pro has an analog line stage that's every bit as good as my mid-'80s VSP Straightwire II, and that's saying something.
The $169 Cambridge Audio 640P phono stage is way better than the phono stage in my mid-'80s Amber Model 17 preamp, and that Amber was designed for vinyl enthusiasts--it has capacitance DIP switches for the MM phono input. The Cambridge is also *at least* the equal of the phono stage in the Straightwire, which was a $1500 unit in 1985.
PS Audio has the Gain Cell, allowing for variable gain rather than a preamp gain stage and an amp gain stage, with resistance-based attenuation in between. The variable gain stage lowers the noise floor and improves linearity. The Onkyo A-9555 integrated amp also has a variable gain stage, and also benefits from excellent linearity, speed, and transparency. It can also deliver up to 80 amps of instantaneous current, making for a very responsive, quiet, and resolving amplifier.
When I bought my first stereo in 1972, $400 would buy you a respectable 45 wpc receiver from Altec-Lansing, Pioneer, or Marantz. That's about $2200 in today's money. My $474 Onkyo A-9555 would have cost only $96.63 in 1972 dollars, but you couldn't have bought this Onkyo's performance then at *any* price.