The JK Series IV happens to be the cheaper option I'm looking at, and it appears to be in good shape, that might be the way I swing, what can you tell me about it as far as durability and sound, intonation etc goesNow hold ON there just a minute. Wanna throw in something for consideration.
First off, A-4's had 2 different iterations....the earlier one had a traditional pinky table as opposed to a modern style one. Those are nothing to write home about.
Just wanted to make folks aware there is a distinction within the 4 models.
Next....the 4's certainly do not have the tonal and blowing response qualities of the 6's or later....so, yeah, the engraving reads Yanagisawa...but, there's a reason 4's do not fetch aficionado prices the way their later models do.
The ST90 is the way to go.
Regardless of keywork style of the 4, the 90 just sounds better and is slicker under the fingers. I have now serviced or refurbed a half-dozen of 'em. It's a well-built horn, regardless of whether it was assembled in Europe or at KHS/Jupiter. It's a JK design in either case. The IV's seem to start segueing more into a Jupe in some of their specs, FWIW. If that matters any (shouldn't matter much, but might to some).
Arguably one of the most underrated horns in its price category. It destroys the student Yamas and Selmers....