On Mon, 10 Dec 2007 23:04:40 GMT, "William W Western"
wrote:

There are some collectible LPs I see on lists where the
mono version is worth more than the stereo version. I am guessing this is so
because in the transition time stereo outsold mono thereby creating a
scarcity. Or, possibly the stereo effect was so gimmicky audiophiles now
prefer the mono version? snip

No, the latter's usually the case...scarcity. This wasn't the case
with the early stereo era releases, when monaural outsold stereo by
multiples. Not much later, I seem to remember around 1968 onward,
stereo almost always outsold the mono, as stereo players became the
norm.

I remember when the labels started hyping "mono compatible" on their
records, which was a real crock. To what they were referring what
that many early stereo releases, when played back on mono equipment,
would be unlistenable due to phase/time cancellation. This problem
was painfully obvious in many "mixed down from stereo" classical
releases of the era. That's why there were usually two master
mixes...one for the singles and mono LPs, and one for the stereo. By
the end of the 1960s, "mono compatible" stereo masters and disks were
the norm. That's one reason that later mono disks that were outsold
by their stereo counterparts are so desirable to collectors...the
final mix product is completely different than the stereo version. A
good example of these would be the EMI Beatles releases.

One instance of this was when the labels started releasing 45s in
stereo...a non-compatible stereo 45 played, say, on an AM radio
station, would sound like crap due to the phase cancellations
involved. It was this compatibility issue that led many producers to
use simple "ping pong" 3 channel stereo mastering, right off the old 3
track Ampex machines, rather than true stereo mixes. With "ping
pong," there would be no phase/time cancellation problems, as all the
audio would either be in one channel or the other, or if from both,
effectively in phase.

Getting back to "mono compatible" discs...of course, the old, stiff
monaural cartridges, tracking as they did at oodles of grams, would
wipe out (usually) the outer (right channel) track after only a few
plays, rendering the disc useless for any critical listening due to
tons of distortion and a completely missing top end. Most mono
players sold in the late '60s on had a "stereo compatible" ceramic
cartridge which were compliant enough to track the 45-45 stereo groove
wall without completely destroying it in a couple of passes, but only
had two output terminals. I seem to remember Sonotone starting to
provide "stereo trackable" mono "flipper" ceramic cartridges somewhere
around 1965 or so, and they replaced the old mono styles completely
shortly thereafter.