Cartridges

@hysteve 

You have a fairly balanced system. I am familiar with most of the gear you have.

The problem is that the tonearm is the weak link if it is the VPI unipivot and you won't get the best out of a cartridge upgrade.

The conundrum then becomes if you want to upgrade the analogue -then really you should start with a better TT/arm, otherwise you'll sink money.

Simply installing the Axis on a Rega P10 for example would be a significant upgrade in my view, using the VPI as a trade in. The P10 should last you for years.

Alternately with the Volti speakers, as good as the Pass is, you should try and audition some tube amps in my view  - for example the Prima Luna integrated are very good. I think your digital might be a lot more listenable with tube amps driving the Volti's. EL34 based tube amps are what those speakers were designed around.

If you’re not spending $20K+ on your cartridge, you’ll never see an improvement. You certainly won’t from $1k - $10K. 

@OP,  the folks who put down the uni pivot is because it is too difficult for their level of mechanical knowledge to adjust it properly. I change carts back and forth often enough that I can get to fully satisfying results in an hour every time, any cart. Upgrade the cart, forget about those few hot stampers, you want every record to sound better.

I go with @dogberry 

There is magic in many LPs.   Get the cart.

@baylinor   Forget unipivots.  They offer nothing a properly supported arm cannot and will always be unstable.  I have tried them.  You cannot 'adjust' a flawed design.  What to 'adjust'?   It just hangs.

A good cartridge will improve all your records. So if you have lots of records, the answer is obvious.