My Single TT now has 3 Tonearms: MC; MM; MONO
Vintage JVC Wood Plinth CL-P2 with 2 removable armboards, and a 3rd arm added on the narrow left side.
Here’s a CL-P2
Larger Plinth CL-P3 with 3 removable arm boards exists, but, bigger, rare, expensive, and I had the CL-P2
I decided to add a 3rd arm left side of my CL-P2
To fit the narrow width, and fit inside of the dust cover when on, only a compact arm fits.
I found a Mission 744, which is made by Jelco, the 250ST. Short 210mm spindle to post and short rear counterweight design. Many adapter plates exist also
https://www.hifishark.com/search?q=jelco+sa-250+st
Mine, wood plinth, a 3/4" hole for the din cable, 3 wood screws for the surface mounted base plate, done.
MC right side; MM removable headshell rear; MONO left side.
SUT with 3 inputs and PASS feature for MM goes to MM Phono input of Preamp.
https://www.ebay.com/itm/Fidelity-Research-FRT-4-Step-Up-Transformer-MC-Phono-Cartridge/114389428649
https://www.vinylengine.com/library/fidelity-research/frt-4.shtml
I’m washing/selling LP’s on eBay. Playing to verify how quiet, no skips/blips … I realized I was unnecessarily wearing my MC fixed stylus, thus I added the 3rd arm to use MM replaceable stylus. Removable headshell for versatility: ML/Elliptical/Conical
I could not be happier.