recommendation for a high end analog system


I never had an analog system until last month. I bought a 1989 SOTA TT with vacuum/Sumiko MMT arm/Dennon 103R retyped with elliptical/sapphire cantilever. My phono is Kitsune MK5 WBT that is amplified by Don Sach 2 tube preamp and Pass X350.5. My speaker are Sound Lab M545 ESL. The TT has been very   well maintained despite its age. It sounded very good until I heard my friend's system which has the same TT but with Lyra Skala cartridge and first generation Triplanar arm (Spectral pre/amp). His sounded noticeably clearer and fuller. What is the best way to get a noticeable improvement in my system without breaking the bank (or before I have to squint to hear the improvement). I would love to hear some wisdom from analog-philes.
128x128chungjh
I'd spend as much as you can afford on a different cartridge.

The equipment appears to be worthy of spending much more than what a Denon can be purchased for.
Get a Miyajima mc cartridge! A worthy competitor to a Lyra! A Kuzma 4-Point arm would be a significant upgrade too!
I always like to use SUTs (step-up transformers) in front of phono stages with mc cartridges. Bob's CineMags are good ones! I hear more detail and lower noise floors with them compared to a high-gain active stage.
@chakster is correct in that the Denon shines in heavier tonearms@jasonbourne52 is also on point in that the Denon is known to sound best with a good SUT ( even if you have enough gain )
However this is a good time to see how far you can push the existing setup. It will help of you would describe your process to optimize table and cart setup ( vtf sra azimuth zenith ) etc. So others may chime in with their experiences. May as well vett this gear fully before upgrading ( which you may have done but not yet described )