Analog Upgrade - Where to start?

Hello,
it looked like your looking for an upgrade to  your PS Audio Stellar phono stage. I doubt you would have a problem selling that. You should match the phono preamp with the TT or at least the cartridge. 
I am going to suggest Sutherland products. https://sutherlandengineering.com/home/
I think you should take a listen to the Little LOCO or it’s big brother the Phono LOCO. I have tried the Sutherland TZ Vibe (MC only) and the Little Loco. They are so good. Sutherland has a little something for most everyone. I think for $3800 the Little LOCO is a steal for what it does. Luckily the store I buy gear from is a dealer. They are located in the Chicagoland area. They let you try in your home before you pull the financial trigger. https://holmaudio.com/
I think the TZ Vibe is $1400 and the Little LOCO is $3800. One really cool thing about these two phono preamps is you don’t need to mess with setting up the cartridge loads.  “The endless worry about finding the ‘best’ load value is obviated.
The cartridge must be the moving coil type.”Plus, you can add 6db of gain if you need it. I listened to it on the VPI Prime Signature with the AT 1000 cart on the normal gain setting and it sounded really good. Same thing for the TZ Vibe on the new VPI Prime 21 with the Shyla cartridge. (AT Art 9+) If you want to go higher or need MM Sutherland has options for that too. I am waiting for my Linn Axis motor board to be rebuilt so I have to wait to decide what is best for my TT and system but it will be a Sutherland. I hope this helped. 

I would like to thank everyone for the great advice and input.  It’s been very helpful and further confirms to me that the turntable and tonearm do not need to be changed.  
Some people have mentioned that there is a place to list out system components (perhaps  in my profile).  I will try to figure that out and update it.

@chilli42 thanks for your system info.  Just wanted to make sure your system was transparent enough to hear changes/upgrade to your analog front end which it apparently is.  However, I’m not familiar with Silent Source interconnects so not sure if adequate for your audio chain.

I agree that both cartridge and phono preamp upgrades should be your next sonic upgrade steps. The cartridge change would move you towards the sound you’re looking for while the phono preamp upgrade would increase the quality of the sound and should lower the noise floor.

You highlight " introduce more dynamic sound, detail" ...I would strongly suggest auditioning a Funk Firm Achromat if your TT has the VTA height adjustment to accomodate its 5mm thickness. I recently put one on my platter and realised I could have spent the rest of my life swapping out components, cables, cartridges in a futile search for those qualities and all I would have achieved is better and better amplification of the resonances trapped in the vinyl itself. I was astounded at the difference it made. Cork, Rubber and felt are insulators that keep the energy created by the stylus trapped inside the vinyl. The Achromat absorbs and dissipates it. And it works.

@rauliruegas I agree that every cartridge has its own signature and 'natural color'. That is exactly why it makes sense to have more than one, because no single cartridge can do everything right. There is no 'best' in this game. And I will stand by my remark that in this sense today's 'best' cartridges are not generically 'better' than the 'best' of yesterday.

Changing cartridges has become one of the more enjoyable aspects of my audio life, but it is also good to have a benchmark, a reference you can return to in order to reset your ears. For me that's the Van den Hul Colibri XPW Blackwood, a low output version with platinum coil wires (no longer in production). This does many things better than most, but not everything.

Obviously this is all very much system dependent, so it makes sense to select a phono amp that is as 'neutral' as possible and adds as little of a signature or 'natural color' of its own. I don't know if the Stellar meets up to this, but I agree SS is probably 'best' in handling the extremily low voltage levels generated by MC's.

The rest of the OP's system is also very high level: the speakers are known for their dynamic capabilities, solid class A power amp and a preamp that provides the 'natural color' of tubes which many people value. To be honest I have my reservations about the Stellar's capability to keep up with this quality level. It may be the overachiever some people claim it to be, but that's still no guarantee it is a great match for the ARC pre and Pass power, which are often used together and seem to work very well as a team. So your first priority should be to make sure that the phono amp has good synergy with these, before you start messing around with the 'natural color' of top dollar MC's.