by jukeboxexpress »
Wed Dec 19, 2012 7:25 pm
How do you tell the difference between mono and stereo records?
First, as a correction, stereo 45's began reappearing in 1968 on BUDDAH AND ELEKTRA releases. Most other 45's were still mono only. BUDDAH had usually "DUAL 45" printed on the label and ELEKTRA had "STEREO PLAYABLE IN STEREO AND MONO" all in small letters.
As mentioned before, there should always be some sort of indication in the numbers printed on the labels or in the trail-off of the record. Most stereo 45's will have stereo printed on the label. On promo 45's, when the same song is on both sides, if there is a stereo/mono difference, it should be printed on the labels. On Warner/Reprise commercial issues of 1970 and later, there will be an "S" after the matrix number. On a few that used the CSG stereo process, usually "COMP." will be in the trail-off. Atlantic/Atco will have an "ST" prefix in the matrix number. Most Atlantic/Atco 45's were only available in stereo on the promo copies until 1973.
A&M started issuing commercial stereo 45's in 1970 also. One of the first was "Close To You" by The Carpenters(issued in both stereo and mono). A&M will usually have "STEREO" printed on the label and an "S" after both the record and matrix numbers. As an early pioneer user of the CSG-Haeco system, these are always stereo(if you can call it that), and will indicate the use of the system on the label but will only have "CSG" in the matrix number scratched into the trail-off. Atlantic/Atco also experimented with "CSG", but mostly in mono, with an indication printed on the labels. CSG recordings will have a rough texture to the groove surface that you can both see and feel, plus the grooves will appear darker.
Most all Bell 45's were mono only, unless promo copies. Bell had an "S" at the end of the matrix numbers on their stereo 45's. Even some of the Bell promo copies that had stereo printed on them were actually mono. Virtually all Arista 45's are stereo only, unless they are promo copies. When Bell distributed the Big Tree label, most of the commercial copies were stereo. Before Bell, BT 45's were all mono(Ampex...etc.). After Bell, Atlantic/Atco distributed, all commercial 45's were stereo.
You can also usually tell by looking at the grooves. On a mono recording, the grooves will resemble a snake pattern with the groove wall following a pattern traveling in unison side to side. On a stereo groove, especially wide separation, there will be differences in the left and right groove walls, if you can imagine a constant series of figure longitudinal 8's.
-Dan S.