2SK170 Datasheet says "Not Recomm for New Designs"?? ...

Nope. Discrete audio transistors are a niche market. The vast majority of the consumer market has gone integrated (op-amps, monolythic ICs, and class-D). There's not enough profit to continue producing these specialized JFETs. There are some substitutions that are close, a bit of searching through the forums can find a few threads with the info.