Suggestions For Analog Upgrade - Tonearm or Phono Stage?

I agree also on the Helius. Small companies have a habit of disappearing.

Helius Designs have been in business since the early 1980s.

I have  a Audiomods Micrometer Series Five Tonearm with the continuous Wiring from Headshell to RCA Connectors at the Phonostage.
I also have an SME Series IV.
Neither of these are in use at present and have been on the Sub's Bench since 2019 when a Bespoke Design for a Tonearm was produced for me using a Donor Tonearm to produce the arm that remains in use.

I can't comment on whether a change of a Phonostage or Tonearm will produce the changes to the Vinyl Source of the System that is being sought. 

Very recently I had a experience that had a profound impact on my thoughts about where I am at with my set up, to elaborate.
I took up the offer of a invite and have been present at a Debut and Demonstration of a  New Design for a Tonearm. I was briefed over time on the design and progress, so the invite was appreciated and I was keen to encounter this experience.
The end result is that the experience undertaken has left such a positive impression, where the Demonstration has shown the New Design is able to outperform my preferred Tonearm.  I have been at a loss to explain the exceptional delivery capability and the attractiveness of the presentation that was on offer from the New Design Tonearm.
I could not have understood any assessment offered by other attendees,
but as a follow up have fully understood all the commentary being passed on.
This was an experience needed to be encountered and evaluated against personal recollected impressions from previous experiences.

With that in mind, I would suggest to get out and listen to a few of the shortlist suggestions and other suggestions be offered.
A experience might be encountered that could change the plan full circle.
That type of impression and experience encountered will not be had just through discussing options on a forum.

  

@pindac, yes that's great advice. As part of the leadership of a very active local audio group in my prior location, I was spoiled by the regular opportunity to listen to dozens of great systems and do regular comparisons/shootouts, etc. with many diversely and well-informed enthusiasts. Once the world gets a bit safer, I'll be hoping to hook up with Austin TX area folks to share some music, learning and a drink or two. 
For now, I'm making audio plans in relative physical isolation.

FWIW, how would you compare your Audiomods to your SME? Cheers,
Spencer

tough question , always more difficult with a well sorted system as yours is. The Dyna you have punches well above $. i would keep it and wear it out. Kuzma is safe bet, 2 bad the newer Triplaner do not fit SOTA.
best to you
Jim

Listening to and using a tonearm are the final steps in evaluating an arm if you get the chance. Tonearms are straight forward mechanical devices. Most of the elements of a tonearm's design are clearly visible. 
My own approach involves a set of criteria which I think are essential in achieving the best performance. Once those criteria are met it becomes necessary to evaluate criteria which are not so obvious like the resonance characteristics of the arm tube, ease of use and quality of construction. Using and listening are the best ways to do this but unfortunately, many of us to not get the opportunity and have to go by the opinion of others.

With arms that are being modified by secondary parties you can not be sure of what you are getting. SME is a very technically sophisticated company. I doubt anyone is going to make a significant improvement in performance with one of their arms and is more likely to do the opposite. Why would I buy an arm that needs to be improved? There is nothing I can do to a Schroder CB to make it perform better.