Mono records played on a stereo rig are one thing, but stereo records played in mono on the same rig, do not produce the same result. One likely result is loss of ambiance and high frequency information. I agree with Shadorne, look for a system issue..
Mono VS Stereo
Hello,
For the last few years I stopped listening to my system in stereo mode and now only listen in mono. As soon as I started listening in mono my listening enjoyment went up about 300%. No longer did I become fatigued by the (Man made) stereo (Effects) created by the engineers in the studio. I grew to hate following these effects from the left speaker to the right speaker and back again with some recordings. When you attend a live performance be it Rock, Jazz, synphony or whatever, the sound comes at you in mono not stereo (Unless of course the sound man has other ideas. But as far as the band and the actual instruments are concerned there is no such thing as "Playing" in stereo. Give it a try, listen to your records or CD's in mono ( I hope you all have a mono selector on your preamps) it will be hard going back to stereo listening plus the soundstage and the way the "Band" comes across will be really cool.
For the last few years I stopped listening to my system in stereo mode and now only listen in mono. As soon as I started listening in mono my listening enjoyment went up about 300%. No longer did I become fatigued by the (Man made) stereo (Effects) created by the engineers in the studio. I grew to hate following these effects from the left speaker to the right speaker and back again with some recordings. When you attend a live performance be it Rock, Jazz, synphony or whatever, the sound comes at you in mono not stereo (Unless of course the sound man has other ideas. But as far as the band and the actual instruments are concerned there is no such thing as "Playing" in stereo. Give it a try, listen to your records or CD's in mono ( I hope you all have a mono selector on your preamps) it will be hard going back to stereo listening plus the soundstage and the way the "Band" comes across will be really cool.