I am enjoying my analog system, but what can I do to improve?

As Lewm mentioned, the Quad 57’s are a small electrostatic speaker that might work but it doesn’t provide a lot of low end.
Also, those jokes about electrostatic speakers being for audiophile masochists…. I just had my amp tech over today to clean my output relays and found that my right Quad was arcing and making a popping noises. So back to my speaker tech to replace a panel or two.

Synergistic Research has a new and expensive record mat. Anybody used or heard one of these compared to a Herbies or Funk Firm?

@chungjh for all I know the system /room are working fine but as noted above not the usual space for a dipole. If you are happy with how its working I would stand by my first post. Controlled directivity,   and corner or rear wall boundary speakers would seem more suited if you want to think about a speaker change. I happen to be scheduled to test, and if that goes well represent, a new and very interesting speaker for rear wall boundary placement, and of course there are vintage horn speakers that fit these requirements too...

Move to good quality digital. You will get less noise and at least another 12 - 15 db of dynamic headroom 😉

You will also get punchier bass, more precise treble and crackle free mids. 

The 1200G is a bit of a pig to change tonearms on - and there's very limited clearance for the arm pillar vis a vis the baseplate, especially since the platter is so low profile and the arm often needs to come down a long way to get the correct VTA. I did an SME IV swap on one recently (not my own deck) and it just about worked. Though, it certainly did improve the deck. However, I would just upgrade the entire turntable because it's bad value to end up with a redundant arm that doesn't really fit anything else, versus trading in the complete deck for an alternative - there's a myriad of choices.

As has been said, any of the Pass preamps would work well.

I suggest consideration of the Parasound JC3+ phono stage which is excellent value for money on a price/performance basis.

Simplify signal chain and go for unified voicing?

1. Given room size, sell the two amps and replace with Pass labs pure class A (XA30.8) [that seems like a definite]

2. Add Pass pre and phonostage [or phonostage to taste]; sell the other stuff

3. Not sure enough space for dipoles to breathe.  Try high efficiency on the smaller side - Coherent, Trenner & Friedel, Zu, whatever - you are at nearfield listening distance anyway

Could be breakeven if you buy used gear. Certainly much less than $7k

WIll be a simpler, higher efficiency system maybe better suited for room size.  Will certainly sound a lot different

Let us know what you decide!

Have a great day