Wednesday Jun 26


In The Astonishing Hypothesis (1994) Nobel laureate Francis Crick, one of the DNA guys, describes a study on selective attention in hearing that makes clear the need for a stereo/mono switch for playback of single channel source material.   The main sources this affects are mono LPs, 45s, and 78s, but I have a few CDs were mastered from mono LP sources in which the production engineers did not take the obvious and necessary step of mixing down the left and right channels.


For years I've been insisting that a proper phono stage must include a mono switch for paralleling the channels when playing a pre-stereo LP, 45, or 78. Remember there were about 75 years of commercial recording before stereo discs hit in 1957. Recordings made during that time can still be played on modern equipment, but benefit greatly from single channel rather than stereo playback. Since CDs hit, phono preamplification and equalization have largely disappeared from home audio gear and the stereo/mono selector (sometimes with reverse stereo or variable blend features) also disappeared.

Here's a very basic DIY project that will let you combine left and right channels for recording from mono vinyl or shellac or listening to marginal FM or for whatever other reason you may find for doing so.

Here's an idea for headphone manufacturers. I'm offering it free of any obligation.  We need a music-quality single on-ear phone or in-ear bud that uses a stereo plug and blends the two channels into a mono signal for one-ear listening.

I'm getting the odd impression that monaural sound has become cool.  I mean no disrespect toward the first 75 years or so of recorded sound.  Mono itself isn't odd.  Recent developments surrounding it are.