Tone controls effect the time domain and phase characteristics of the single. Most operate over too great a range for them to be useful. They also affect the harmonic structure of the music.
Manufacturers who design for the so called "High end" will not use tone controls for the very reasons I stated above. High end is about sonic accuracy for better or worse.
As for the 12 o'clock setting, many of the manufacturers have the tone control circuit out at this position. There is a benign (null) point with most all of them somewhere. NAD used this back in the 70's. Also, some feature a tone control defeat switch so you can have both features.
Manufacturers who design for the so called "High end" will not use tone controls for the very reasons I stated above. High end is about sonic accuracy for better or worse.
As for the 12 o'clock setting, many of the manufacturers have the tone control circuit out at this position. There is a benign (null) point with most all of them somewhere. NAD used this back in the 70's. Also, some feature a tone control defeat switch so you can have both features.