You can play mono lps with a stereo cartridge. The reverse, however, may not be true--some mono cartridges would be, at best, hard on a stereo LP.
Mono cartridges are of interest because they can offer better performance for a mono LP since they are designed for the specific task. IA mono cartridge should pick up less surface noise, and offer overall better performance. However, the downside is that it costs more--between $50 and $100 on up for the cartridge, and you need to have it set so it's either on a removable headshell or on it's own turntable. Thus, if your mono lp collection consists of two or three records, it's probably not worth it. But if you have a large collection, it could be a good investment.
There is a good review on Audio Asylum about one mono cartridge. (http://www.audioasylum.com/cgi/m.mpl?forum=vinyl&n=265943&review=1)
Mono cartridges are of interest because they can offer better performance for a mono LP since they are designed for the specific task. IA mono cartridge should pick up less surface noise, and offer overall better performance. However, the downside is that it costs more--between $50 and $100 on up for the cartridge, and you need to have it set so it's either on a removable headshell or on it's own turntable. Thus, if your mono lp collection consists of two or three records, it's probably not worth it. But if you have a large collection, it could be a good investment.
There is a good review on Audio Asylum about one mono cartridge. (http://www.audioasylum.com/cgi/m.mpl?forum=vinyl&n=265943&review=1)