hrabieh, optimizing mono playback can become complex, but basic enjoyment doesn't need to be. Yes, there can be considerations for when the record was issued, groove width, even EQ. But I believe the first consideration is which mono records will you listen to?
There are multiple reissues now of older mono LPs. Since mono cutter heads are no longer available (so far as I know) these are cut with stereo cutter heads. This simplifies matters as a stereo cartridge stylus should be just fine. A mono switch may still be beneficial, such as Elliott suggested, to reduce background noise.
However, if you intend to play original monos from the late '40s to early '60s, by which time initial mono releases ended, then there may be no simple playback solution if you are concerned about sonics. A modern stereo cartridge can be used but will not be optimized for stylus size, pickup type (no vertical groove information, only noise). Also multiple EQs were utilized by different labels (requiring selectable settings). So the best answer there is a second cartridge and specialized phono stage, which you want to avoid, at least to begin with.
There are multiple reissues now of older mono LPs. Since mono cutter heads are no longer available (so far as I know) these are cut with stereo cutter heads. This simplifies matters as a stereo cartridge stylus should be just fine. A mono switch may still be beneficial, such as Elliott suggested, to reduce background noise.
However, if you intend to play original monos from the late '40s to early '60s, by which time initial mono releases ended, then there may be no simple playback solution if you are concerned about sonics. A modern stereo cartridge can be used but will not be optimized for stylus size, pickup type (no vertical groove information, only noise). Also multiple EQs were utilized by different labels (requiring selectable settings). So the best answer there is a second cartridge and specialized phono stage, which you want to avoid, at least to begin with.