A true mono cart is one with no vertical compliance. Such carts usually track at more than 3g. Tip size is another factor. A 1 mil tip can be used on a stereo record, but I wouldn't want one tracking with excessive weight. For a discussion of this, here's a VE thread. Poster Guest, is Luckydog:
http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=48089
From AT:
The AT33Mono is made specifically for use on mono systems. It has a horizontal coil, and so in principle only generates electricity horizontally.
The AT33Mono produces sound to a very high quality because it does not easily pick up unnecessary strain components from distorted or scratched records, producing audio that you couldn't possibly get from a stereo cartridge.
The AT33Mono also has appropriate compliance in the vertical direction, so will not cause damage to stereo records. Enjoy those well-known classic mono records of yesteryear with the AT33Mono.
That does not sound like bridged channels to me. Even MMs with mono output are not bridged (strapped or parallel connection). The coils are connected in in such a way to cancel most vertical cantilever movement. As long as a cart, either MC or MM, has vertical compliance, vertical rejection will be imperfect. Nevertheless, Ortofon is correct about using a stereo cart on a mono record. A mono switch cancels 30dB of vert noise on a mono record, but can not correct stereo differences described.
Even the Miyajima Zero has some vertical compliance, it's very little and not designed to play a stereo LP.
http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=48089
From AT:
The AT33Mono is made specifically for use on mono systems. It has a horizontal coil, and so in principle only generates electricity horizontally.
The AT33Mono produces sound to a very high quality because it does not easily pick up unnecessary strain components from distorted or scratched records, producing audio that you couldn't possibly get from a stereo cartridge.
The AT33Mono also has appropriate compliance in the vertical direction, so will not cause damage to stereo records. Enjoy those well-known classic mono records of yesteryear with the AT33Mono.
That does not sound like bridged channels to me. Even MMs with mono output are not bridged (strapped or parallel connection). The coils are connected in in such a way to cancel most vertical cantilever movement. As long as a cart, either MC or MM, has vertical compliance, vertical rejection will be imperfect. Nevertheless, Ortofon is correct about using a stereo cart on a mono record. A mono switch cancels 30dB of vert noise on a mono record, but can not correct stereo differences described.
Even the Miyajima Zero has some vertical compliance, it's very little and not designed to play a stereo LP.