You can have a look at the alto-neck thread I started (https://forum.saxontheweb.net/showthread.php?336794-Replacement-Necks-for-Alto-in-General). There are a lot, which also fit to Yanagisawa altos.
The list was getting much bigger than I thought. I believe all of these are great necks.
I just tried 2 Gloger alto necks on my Selmer SBA. They were good, but the difference to the original neck was quite small. Karsten Gloger also offers them for Yanagisawa.
My daughter uses a Yamaha G1 on her Yani 880 alto with good results.... makes it a bit more free-blowing. You could find a used one for not a lot of dough, and sell it for what you paid if it's not what you're looking for.
A forum community dedicated to saxophone players and enthusiasts bought to you by Harri Rautiainen. Come join the discussion about collections, care, displays, models, styles, reviews, accessories, classifieds, and more!