There seems to be some confusion with people mixing up classical and pop/rock recording practices. Recording classical music is completely different than recording pop/rock. In general terms classical music is recorded to sound like a performer actually performing in a real acoustic environment. Pop/rock recordings do not adhere to that standard and have a "whatever works" mentality. In other words, classical recordings are trying to capture a great performance and pop/rock recordings are trying to produce a hit record.
As a result the recording techniques for each type of music is very different. Classical techniques is intended to be unobtrusive and virtually inaudible to the listener. The best way to achieve this goal is to have a very simple recording chain. Pick a good sounding hall, a well rehearsed and talented ensemble, 2 to 5 microphones (even for stereo more than 2 mics are needed to balance direct vs. hall sounds), some great mic preamps, a minimalist mixer and record directly to tape or hard drive. No overdubs, no EQ, no compressions, etc. Contrast that to even a stripped down sounding pop/rock recording. Recordings pieced together from individual instrumental tracks recorded in different studios. Drums playing to click tracks. Mixing MIDI performances with real players. Autotune. Adding reverb to intentionally recorded dry performances. And finally compressing the signal to the point of distortion (and beyond) so that it jumps out at the listener when played as part of some random playlist.
Other than economics there is no reason why current classical recordings cannot sound as good, or even better than the best "golden age" recordings. Current mic, preamps and mixers are better than the old equipment. The old equipment is rightfully legendary and revered, but it is 50 years old and worn out. The new recreations of the classic gear are better performer today. There is no magic to the golden age recording techniques. It was simply the dedicated application of a craft by skill artist and engineers. There's no technical reason why that same expertise and craftsmanship cannot be put into use today.
As a result the recording techniques for each type of music is very different. Classical techniques is intended to be unobtrusive and virtually inaudible to the listener. The best way to achieve this goal is to have a very simple recording chain. Pick a good sounding hall, a well rehearsed and talented ensemble, 2 to 5 microphones (even for stereo more than 2 mics are needed to balance direct vs. hall sounds), some great mic preamps, a minimalist mixer and record directly to tape or hard drive. No overdubs, no EQ, no compressions, etc. Contrast that to even a stripped down sounding pop/rock recording. Recordings pieced together from individual instrumental tracks recorded in different studios. Drums playing to click tracks. Mixing MIDI performances with real players. Autotune. Adding reverb to intentionally recorded dry performances. And finally compressing the signal to the point of distortion (and beyond) so that it jumps out at the listener when played as part of some random playlist.
Other than economics there is no reason why current classical recordings cannot sound as good, or even better than the best "golden age" recordings. Current mic, preamps and mixers are better than the old equipment. The old equipment is rightfully legendary and revered, but it is 50 years old and worn out. The new recreations of the classic gear are better performer today. There is no magic to the golden age recording techniques. It was simply the dedicated application of a craft by skill artist and engineers. There's no technical reason why that same expertise and craftsmanship cannot be put into use today.