Thanks for chiming in OP. I would challenge your precept that $4K is a "modest" investment for an "upgrade" to a source, let alone, another $9K in "tweaks" for most people on this forum. If you've got the green and it's worth it to you, that's great. At that level, I would hope that the improvements are noticeable.
To be fair, I went back and did some listening with my clock on and off recently as a result of this thread and I was able to perceive some minor differences in sound quality, but nothing that I could specifically put my finger on or that made it worth the not so modest amount (to me) that I spent on the clock.
Now last night I added a new phono stage to my system that cost a little over $3K, and... yowza! Money well spent! There were significant improvements in separation and detail of instruments and voices, soundstage, pace and rythym, and the overall body of the music. These were things that I could easily perceive and describe.
To be fair, I went back and did some listening with my clock on and off recently as a result of this thread and I was able to perceive some minor differences in sound quality, but nothing that I could specifically put my finger on or that made it worth the not so modest amount (to me) that I spent on the clock.
Now last night I added a new phono stage to my system that cost a little over $3K, and... yowza! Money well spent! There were significant improvements in separation and detail of instruments and voices, soundstage, pace and rythym, and the overall body of the music. These were things that I could easily perceive and describe.