Another “How to choose an arm” question

Dear @holmz : Look for no unipivot designs, no matters what. Even that you like stay away of knife bearing designs.  Read carefully the tonearm manufacturer site information, is very important. Look for well damped tonearms. Medium mass is fine. Reading reviews from TAS or STPH could help too.

Now, even that your cartridges or any cartridge can be well matched about the resonance frequency ideal range same cartridges in different tonearm sounds a little different. Each tonearms it self vibrates/resonates different and are damped in different way but any good choice that you decide will performs really good. Today there are only a few tonearms that you could say: this is a bad tonearm. There are many tonearm manufacturerers.

Each one of us tonearm opinions come from our first hand experiences through our room/system that never is near the one you own, so be very carefully here and if you have near tonearm retailers then go to listen it and the same is you have audio friends near your place and I hope you already definied very specific targets for your system that can match it according your MUSIC/sound priorities  You need this kind of reference and when listening to other systems or even in yours you need to know exactly what to look for in LP tracks to really know you are near your targets:

https://www.kuzma.si/tonearms

@holmz - Since the RB3000 was recomemnded I would also suggest taking a look at  the Audomods Arms

www.audiomods.co.uk

I've had a the old Classis Series 3 with the Micometer VTA for about 11 years and have no thoughts of changing it. The new Series 6 has many improvements

Jeff at Audiomods will answer any questions you have about his arms.

He can also make mounting plates to suite your turntable in many cases

His arms are superb, finely crafted and provide exceptional performance to any turntable

He can also recommend cartridges that match his arms perfectly

Hope that helps - Steve

@holmz , You are getting some really great advice here. As a long term Sota user I would like to add some thoughts. There are several great arms out there that fit the Sota perfectly. As Lew suggests it is always better to stay on the light side as you can always add mass but taking it away can be tough. Your Sota suspension is tuned for a specific tonearm mass. Depending on the age of your table it can be done by adding/subtracting lead shot from a well or using a specifically weighted tonearm board. Once you buy the arm you want to use, weight the arm itself with all the parts attached. Do not weight the cable. Then call Donna at Sota with your Sota's serial number and the tonearm weight. She will supply you with the correct arm board. 

Tonearms that I know work beautifully on the Sapphire and are of top notch design are the Kuzma 4 Point 9, the Origin Live arms, the Rega arms, the Audiomods arm , SME arms and the Schroder CB. There are very few cartridges out there that can not be made to work in any of these arms. IMHO the three best arms are the SME V, the Kuzma 4 Point9 and the Schroder CB. These three hit all design points I want to see in an arm. There are others out there like the Tri Planar which are great arms but will not fit the Sapphire without modifying the plinth.

Would upgrading the arm be worthwhile? I think so, particularly if you go with one of the three arms I mentioned. You will certainly be able to use more cartridges in the medium compliance range. Your SEAC arm is going to work best with something like a Koetsu, cartridges in the lowest compliance group. 

One more point is that you can upgrade your Sota to the Eclipse drive system, the magnetic bearing,  and even a vacuum system. Very few tables can take you that far.