[Vintage-Audio] What Did They Really Do?

[Duane B. Fischer, W8DBF]

Back in the sixties and seventies a number of devices hit the stereo shops that
were supposed to make listening to FM and FM stereo and reel to reel tapes much
better. Among them the DBX, Multiplex and others 	
	
What did they 'really' do and how much of those claims were just hype?Did any of
you actually use them and what are your thoughts?	
	
Duane W8DBF