Rega Planar 3 upgrades

I took Tooblue's advice and purchase a Vinyl Source custom arc protractor for Rega arms.  I'll start with this since it's so affordable.  They mentioned I could use this same protractor for my Clearaudio Concept. 

Cartridge Arc Alignment Protractor. For use with Rega Tonearms. | vinyl (thevinylsource.co.uk)

I do like the Rega sound. I like my Concept better, but that magnetic bearing tonearm is super sensitive to floor vibrations.  I've had to relegate it to my basement system where walking across the floor is a non-issue.  It could be I just prefer the 10x5 over the 2M Bronze.  Those systems are apple and oranges to each other as well.

In regards to my newish unused Clearaudio MM cartridge.  I do have a third system which consist of 90's era Rotel gear (972 pre, 980BX amp) with DCM Timewindow 3 speakers that I wouldn't mind a table on.  Seems like anything newish comes with a cart.  I want to find something inexpensive without a cart to play around with setup.

Buy a used Dual 502, 504 or 505 model.  
Or…a Technics DD with S shaped arm. 
Many out there for sale under $400.00.

I bought a barely used Rega P1 that came with both the Rega cartridge and Nagaoka MP-110 cartridges for $350 CAN. Owner decided to go with Rega P3 for better sound and was outside the return window on P1. The interesting part was the he was totally deaf, couldn’t hear me knock on door or doorbell.

It is possible that it would be cheaper to sell your P3 and purchase a P6 in its place. I think highly of Rega's but I don't like felt mats. Ringmat Solutions or some other high quality brand would be my manner of course.