Goofy, lots of questions on the mono subject and that is not as simple as one might first expect.
Original mono cartridges were designed for lateral motion pickup only. Stereo cartridges added vertical motion pickup (although stereo is a 45/45 configuration, that is beside the point here). Many mono fans recommend "true" lateral motion pick up only since that eliminates any vertical noise component, thus quieter playback. That can be important with older records.
It is true that some current mono cartridges are simply stereo models which have been strapped internally for mono playback. For example, some claim the Grado monos are simply strapped stereo cartridges. I have not seen the definitive answer to that question. Similarly, some claim a mono switch on the preamp or phono stage will accomplish the same result as a strapped stereo cartridge. That seems reasonable to me but I have never heard that comparison.
Next is the issue of styli as Lew mentioned. The size of the cutter head (from original mastering) changed over the years so it could depend on the vintage of the LPs you want to play as a guide to which mono cartridge to choose. Mono cutter heads are no longer available so modern mono reissues are cut with stereo cutter heads, thus "modern" elliptical profile styli may be better for playback.
Beyond this is the question of EQ. The RIAA curve was approved around the time of stereo LPs (1957-8) but not all record labels began using that right away. So again, it may depend on which mono records you intend to play. If they are all recent mono reissues, an elliptical stylus of some design and RIAA playback will be fine. But if you have records from the late '40s - early '50s or late '50s -early '60s then you may benefit from more research before choosing. I suggest searching "mono" here and on Vinyl Asylum.
Original mono cartridges were designed for lateral motion pickup only. Stereo cartridges added vertical motion pickup (although stereo is a 45/45 configuration, that is beside the point here). Many mono fans recommend "true" lateral motion pick up only since that eliminates any vertical noise component, thus quieter playback. That can be important with older records.
It is true that some current mono cartridges are simply stereo models which have been strapped internally for mono playback. For example, some claim the Grado monos are simply strapped stereo cartridges. I have not seen the definitive answer to that question. Similarly, some claim a mono switch on the preamp or phono stage will accomplish the same result as a strapped stereo cartridge. That seems reasonable to me but I have never heard that comparison.
Next is the issue of styli as Lew mentioned. The size of the cutter head (from original mastering) changed over the years so it could depend on the vintage of the LPs you want to play as a guide to which mono cartridge to choose. Mono cutter heads are no longer available so modern mono reissues are cut with stereo cutter heads, thus "modern" elliptical profile styli may be better for playback.
Beyond this is the question of EQ. The RIAA curve was approved around the time of stereo LPs (1957-8) but not all record labels began using that right away. So again, it may depend on which mono records you intend to play. If they are all recent mono reissues, an elliptical stylus of some design and RIAA playback will be fine. But if you have records from the late '40s - early '50s or late '50s -early '60s then you may benefit from more research before choosing. I suggest searching "mono" here and on Vinyl Asylum.