How close to the real thing?

This is incorrect. The Ampex 351 tape machine, used by both RCA and Mercury (and a host of others) has a zero-feedback recording circuit. Neumann microphones use small tube preamps which are zero feedback. I can go on but you get the point.

Sorry Atmasphere, but you're mistaken - recording, mastering, and broadcast equipment all does indeed use a variety of "feedback design techniques and circuitry, going back to almost the very start of electronic recording," as Fas42 states. Specifically, the Ampex 350 and 351 used frequency-dependent negative feedback in the cathode circuit of the record output tube, and negative feedback around the playback head amplifier for playback EQ. Additionally, the 351 had a push-pull (12AU7?) transformer-coupled line-output amp with a separate feedback winding for global NFB, very similar to a little transformer-coupled power amp.

And then there's the record cutting lathe - virtually all high-fidelity cutting heads use negative feedback from a separate winding to provide global negative feedback from the motion of the cutterhead back to the cutting amplifier.

Do Ayre and Pass use zero feedback desings in their amps? I only know they sound really good.

Hi Kirkus, I just pressed on your system and I'm so happy I did. How very cool! To saner times...

Wow, that JBL Marantz Mac setup is something else!

Hi Kirkus, that was not what I recalled so I looked up the Ampex schematic... Its not the record head that has feedback- prior to that the record calibration circuit does use a feedback mechanism. The rest of the circuit has none.

I did think about the playback after posting :/

Of course LP lathes do use feedback, primarily used to control resonance. You can't get channel separation in a Westerex 3D, for example, if you don't use feedback. However there is work being done to this day to try and find a way around that. Apparently feedback is not popular with mastering engineers and for good reason: if the electronics even turn on in the wrong order at power-up, the cutting head can be destroyed.

I have a set of Western Electric mic preamps that are zero feedback. I pulled them out of a dumpster about 30 years ago and boy am I glad I did. They are really transparent, after being updated with Jensen transformers and otherwise rebuilt.