Thank you all for the detailed and informative responses! It’s great to be able to learn not only from your specific nuggets of insight and particular product suggestions, but also to get to aggregate across so many suggestions to get a kind of consensus. (:
Summarizing across the posts above, I’m hearing:
1) Having the speakers on the credenza is a major limitation: try to fix or at least mitigate issues caused by that first.
2) Then, roughly in order of number of "votes", first speakers, then phono preamp, phono cartridge, and maybe interconnects/speaker cables are the recommendations for where to upgrade.
Then, there were some good questions raised:
Q: What cartridge is being used? (@mswale @audio_rd_uk @oceanica) --> the stock Pro-ject MM cartridge the T1 came with. I replaced the stock Ortofon 5E stylus with an OM10 (because our curious 6-year old bent it...)
Q: What is the budget? Something like $1-2k now, up to $5k or so over the next few years. Given that speaker position is so compromised, I think that places a natural ceiling on how much it makes sense to spend.
Next, let me update you on what I did. I first put a set of Herbie’s Fat Dots under the speakers, and tweaked speaker position some more (a little further from the back and side walls). This seemed to make a pretty obvious difference in the tightness of the sound, especially in the lower range.
Then, I noticed a pair of Jamo Concert 8s for sale locally at what I thought was a reasonable price ($350), so after checking that my Rotel amp’s 4 ohm power output exceeded the Jamo spec, I grabbed them and bi-wired them up. Initially I thought they sounded a little restrained -- not quite as open as say, when I had my beloved Vandersteen 1Cs mated to the same amp -- but with more listening I think they’ve grown on me.
On the hunt for a phono preamp next (the T1 has a bypass for the internal stage) -- the journey continues!