Loudness - Why has the industry stopped producing amplifiers with this feature any longer?

The reason it mostly went away was a big trend towards hair-shirt purism in preamps and integrated.  Tone controls, balance control, and loudness (button or variable) all were eliminated at the altar of the fewest possible stages and connections.  This is reflected in Japanese mid-fi components where there's a "straight" or "direct" button that bypasses the tone controls they still incorporate.  Undoubtedly there's a market for a preamp with a variable loudness control, though obviously not to everyone's taste.

Although I eschew "loudness controls" as well as mostly eschewing the word "eschew" (except for this), I don't understand why "measurement" is needed when you can simply LISTEN to the results of applying a control. I have a Loki EQ that's almost always bypassed except for the rare recording that really needs sonic first aid, but otherwise seemingly 99.999% of what I listen to needs (or personal taste dictates a determining action) nothing as far as EQ is concerned...some recordings require me to smoke pot,  but that's another story.

ebm is probably right ie most people never understood or used it.

I am with you twoleftears,

What is really funny, is the people, companies, etc. that eschew this so called "purism" are the first to say Vinyl is the the very best consumer audio format (ignore R-R). What is vinyl? ... it's a minimum of two equalizers, or two compressor/decompressors depending on your view with a variable frequency channel mixer, and a host of other "analog" effects. It is about as far from "pure" as you can get. It takes some serious cognitive dissonance to believe that is pure, but a loudness or equalizer is not.  Some of this is a side effect of believing things not true, like being able to detect small phase differences, etc.

It's almost like the low-fat craze. Never really was any evidence for it, but people blinded believed it, followed it, and got less and less healthy. At least with the THD wars we found out early it was not the be all and end all.

wolf,

I would have one advocacy for measurement. Every few years, someone brings up the very good, but 0 traction idea of playback calibration, usually including reference tones and reference playback level so that the user can listen at the volume level intended to achieve the most accurate playback as intended.