Pumatheman: Welcome aboard.
I couldn't reach any photos on your photo-link so I'm not exactly sure about the soprano you discussed. Nor did other photo links on this site show me any Yanagisawa sopranos of any era.
I listened to the sound clip. Sounded to me like many sopranos with an oboish-quality to them.
I will give you my take on the Yanagisawa soprano line.
First of all, I've owned a MKVI soprano and played several others. I know some players love their MKVI but frankly, I've never played one with a decent scale or a hi-end that spoke with authority. That I sold mine and never looked back speaks a lot about what I think of them.
I recently tried a few of the Kenny G models made in China, but with improvements. I was impressed but thought they were too expensive for what they were. They were essentially MKVI clones, but with standard saxophone-like forked palm keys, NOT the awful design of the MKVI (my opinion).
I've also played a few Yanagisawa S-6 models and while they seemed better than any of the MKVI's I owned/played, I still wasn't impressed enough to buy one in light of the fine players I already own.
I do own a Taiwanese-made soprano MKVI clone. It suffers the same maladies as did all the real MKVI's I know. Like Ed, the in-line palm keys are deal-killer for me.
Back in the 1970's, I bought a Japanese-made soprano, designed like the MKVI and the S-6 . . . a Dorado 600. I strongly suspect it was a Yanagisawa stencil. It too is gone from my closet, but it served me okay. I replaced it with a more modern designed Yanagisawa labeled ELIMONA. As I look back at it, I recall it was an 800-model. The differences between the Dorado 600 (and the VI/S-6 design) were 1)a removable neck; 2) B and Bb bell pads hung underneath the tube as opposed to the B/Bb bell pads being above the tube like the VI, Conns and Bueschers.
Before I wrote this, I went back through some links and threads but wasn't able to corroborate my contention that the 800 Yanagisawa soprano was totally different than the S-6, but I suspect that I am correct. If anyone can confirm or deny, I'd appreciate it (with corroborating photos).
I suspect photos will show that an 800-series Yanagisawa soprano will have a removable neck and the same bell pads as does the more modern Yamahas (62, 475, 675, etc.), the Selmer Super Action series, and the common Yanagisawa S90X/S991 series.
For reference, my favorite all-time soprano is my 1928 Buescher TT straight, but I also enjoy my S992, S901, and curved SC902, among those in my closet. A Yamaha 62 I once played regularly is now in my daughter's possession.
I'm sure that Yanagisawa S-6 you discussed will work fine, it just wouldn't be my choice. DAVE