Why Did Loudness Buttons Go Away? | Audio Science Review (ASR) Forum
Amplifier volume and loudness controls.
Loudness compensation - Wikipedia
Modifications to Loudness Circuit | diyAudio
Details of an old amplifier, closeup view on volume control, balance and loudness Stock Photo - Alamy
The Onkyo A-9010 is the single best amplifier I've heard for anywhere near the price. IMO, it should be the default answer to the “budget amplifier” question that gets asked so often :
Best integrated amplifier with tone/loudness controls | AVForums
The Mysterious Loudness Control: What Does It Do? | Extron
Simple Audio Loudness Control Circuit
Best integrated amplifier with tone/loudness controls | AVForums
Front panel PM6006
I think I have a Loudness button “problem”. | Audiokarma Home Audio Stereo Discussion Forums