Is there a point of diminished returns with amps and Harbeth 30.1s?

Maybe a new cartridge...

Put the turntable on Townshend Pods (or Platform) it will be a huge upgrade. Put the speakers on Podiums, if you can. Might not be convenient if they are moved around a lot. Synergistic PHT and ECT on the turntable, HFT on the speakers (and walls, if possible) and ECT on the amp and other electronics.  

Do all these the improvement in detail, dynamics, truth of timbre and imaging will have your jaw dropping in amazement. You will forget any thoughts of "diminished returns" and be trying to figure out what else you can do. When that time comes PM and I will hook you up.

For my musical taste (acoustic jazz, guitar, classical and jazz piano, cello, guitar based acoustic blues, that sort of stuff) in my space limited co-op on Long Island I'm not sure what's next.  I'm 90% digital/streaming with Qobuz and don't want to upgrade the turntable for now.  I've been thinking speakers but based on what I know after 30 years in this hobby (and with a budget of $5 or $6k) I don't think there is "better" than the M30.1's.  

My system

• Pass INT-25 integrated amp (recent)
• Harbeth M30.1 
• Innuos Zen Mk3 streamer/server (recent)
• MHDT Orchid DAC
• VPI Scout / Dynavector 20x2L cartridge
• Sutherland 20/20 phono stage (recent)
• Mid range interconnects
• Triode Wire speaker cable (recent)

I'm not really itching to upgrade anything. An audiophile conundrum.  

Your fatboy arm deserves better cartridge,
Me too have denon from Zu Audio & both upgrade stylus and still in my system as back up!
but once you move up the chain to 2k cart you hear more and more from record that you never hear before ,everything just more open and clear. So upgrade your cartridge first .
im also use harbeth M30.1 and stuck too because room size .

@honeyooi been down the cartridge route. Spent thousands and always prefer the tone of the 103R, although now I use an Anamighty-built one that costs quite a bit. I have never found a cartridge that duplicates that tone…. with the right SUT of course.