Fact or misinformation?

at the end of the day a cartridge is a compliant lever with a needle and either one or two electro-magnetic coils at the other end (or magnet moving inside a coil).

Mono records only have a single direction of displacement.  Stereo have two.

But either way its a compliant diamond sliding through wiggles. A stereo needle will simply pick up the exact same movement on both channels.

I do not see how this will damage anything.

I admit i've never looked closely at how they align the squiggles

So i find this assertion very unlikely

Sadly, it was the owner of the retail establishment who gave me the no-go request.

One exhibitor confirmed my thoughts as to why some wont. If he puts on a request that isn’t popular, he risks driving out the traffic in the room. I get it, so I make them during lulls in room traffic, or I their LP selection is similar to what I’d like to hear.

I’ve gone to shows over the last 3 decades and that one was a first.

I also got the vibe the dude really didn’t want to take request and just spit out the goofy excuse in hopes I wasn’t informed. Sigh.

Dave, thanks for elucidating one important difference between using a mono cartridge vs a mono switch. I always suspected that cancellation might not be perfect using only a mono switch, and you’ve confirmed it. Nevertheless the mono switch makes a big difference with a stereo cartridge. 

But either way its a compliant diamond sliding through wiggles. A stereo needle will simply pick up the exact same movement on both channels.

I do not see how this will damage anything.

It comes down to whether the playback cartridge has vertical compliance or not.  In the pre-stereo days of mono cartridges had drastically lower compliance in the vertical direction than in the lateral direction since that was the only required direction of movement.   When Stereo was introduced the mono information was kept lateral and the stereo information was encoded in the vertical direction and the coils rotated to 45° so each channel could read both.  This means that you still get the common lateral component to each channel but different vertical components.  The compliance is what allows the diamond to move freely in all directions.  When you playback a record with vertical information with a  cartridge with no vertical compliance, suddenly a battle ensues between a diamond backed by the effective mass of the tonearm and the part of the groove trying to move the diamond in the vertical plane.  Simply put.... something has gotta give.  The Denon 102 is an interesting cartridge since it is one of the first mono cartridges with vertical compliance in line with the horizontal.  It essentially has lateral mono coils and a stereo suspension.  This was needed so broadcast playback could go back and forth between stereo and mono cuts without changing cartridges.

dave