Mono cartridge recommendation

The List: If you rule out * and **, and then

I advise ruling out Line Contact, it narrows the list.

Next: Spherical or Elliptical shape, I chose Elliptical for modern mono grooves and older mono grooves. You gotta choose.

Next: tracking force? replaceable stylus? signal strength?

IOW, limit your choices by functional decisions, then: any sound differences among those fewer choices?

I don't rule out the list.  I just have no idea what the cartridges sound like.  That's way more important to me.  I don't choose my components by a list of specs.  If I did I wouldn't need to post here or ask about the sonic signature of the cartridges.

Sounds like you will be setting up two tables, one specifically for mono.  That is what I do since I have many mono albums.  I recommend you start with one of the less expensive cartridges.  I dipped my toes into mono with the Grado M+ and later the  Myajima Zero.  Improved timbre across the board and female voices are extremely well rendered.  Signal to noise greatly improved with true mono cartridges as Elliottb stated. The question is how deep do you want to go. 

Be aware also that if you use different cartridges for mono vs stereo, then you are introducing another variable to the question of whether a mono switch is superior or inferior to using a mono cartridge.  Could be you like the mono cartridge per se better than your stereo cartridge, or vice-versa. Technically, most modern mono cartridges are stereo cartridges that have been bridged internally for mono operation, which is pretty much what the mono switch does to the signal from a stereo cartridge playing a mono LP.  Any differences in sonics could be due to the fact that in a cartridge, the bridging is done before amplification and application of RIAA correction.  In a preamplifier, the mono switch operates on a fully amplified and corrected signal, before feeding the amplifier.  This has been discussed a zillion times on this forum.

@flatblackround  Thanks for the advice.

My primary table is a VPI TNT 4 with an ET 2.5 tonearm and various MC carts on different armwands

The new one coming is a VPI sold Frankentable with the plinth from a scout, the platter and bearing from a TNT 4, classic signature feet, and just a JMW tonearm base with a bent unipivot point, no armwand.

I have a couple of tonearms laying around, and depending on what cartridge I wind up getting, I'll use a tonearm that matches.

My budget, for me at least, represents dipping my toes in.  The table won't be exclusively mono, but probably will be most of the time.  Mostly because I have yet to decide whether to keep my old Denon for checking out used purchases before I throw them on the main rig.

In a year or so, I will probably reassess the second table, and look for a "forever" tonearm for it along with a better mono cartridge.  This is the second recommendation for the Zero, and it will surely be on my short list.