Rega Planar 3 upgrades

Used vintage Thorens TD125 will be a huge upgrade to P3. You can also use Rega tonearm on Thorens, but the original one insn't any worse.

Good, easy to use protractor: Feickert.

More complex to use and more expensive: Smartractor 

The Vinyl Source custom arc protractor is as good as any and that includes the Mint Best protractors and can be had for $32.00 delivered, do your self a favor and check them out. You will also need a good set of shims to level the VTA for different carts and I would recommend the split spacers that you can loosen the arm and slip the two halves in from the side. I purchased a RP3 used and approached upgrades starting with the cheapest first, changed out the bearing to a ceramic one made washers for the feet to level the table and removed the felt slip mat and replaced it with an Audioquest sorbathane record mat that I had used on my AR EB101 20 years ago (3.2mm thick) these things got me where I needed to be with this table and I really enjoy this table in my headphone setup. I run a Grace F9R with the Soundsmith OCL stylus assembly. WTS, I would not put anymore $ into that table, I would just sell it and move up the chain to a better table. Enjoy the music

Please don't discount @lewm suggestion of the Feickert protractor, although expensive you will never have to buy another one if you change arms/tables in the future. Enjoy the music

I bought a Michael Lim aluminum sub platter and his Acrylic main platter. Also bought the white belt upgrade. I am running a Goldring Eroica XL MC Cart. Very happy with it. The P3 is in the basement on my second system. Paired with a Charisma Audio Musiko phono stage, awesome pairing.

This is probably a dumb question.  I see some cheaper versions of the Feickert protractor on ebay for around $100.  Would those be OK or do I need to spend $300 for the real deal?

You can always count on Ebay to find a MIC knockoff.

You'll gets what you pay for-could be an exact knockoff or...not so much.

From pics it looks just like my REAL jig.

The Grovetracer sub platter is money well spent, you`ll be amazed at how quiet your albums will sound too.

I mean, if you like the Rega sound, go for it. I had a P3 and bought the upgraded power supply, sub-platter and platter. The sound definitely improved. The image was wider, background was blacker, it was able to handle loud and complex passages much better, but I still wasn't entirely satisfied with it. I ended up buying a Dual 1219 from fixmydual.com and liked it much better.  

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.