Yamaha b series (JU)

Hi
I was browsing trying to find out the material of Yamaha b series soundboard with no luck. This series is sold in other markets as JU. Example B1 is JU109.

On their website it is not stated. Yet for U1 and U3 it is spruce and that's mentioned on their US website under the specs. For other pianos there is no mention.

Some people online say it is plywood.

Comparing these pianos to Kawai pianos, all of them have solid spruce stamp on the sound boards. While nothing on Yamaha JU109 and B1. Is it really plywood or Any other wood but spruce?

Current information about the b series Yamaha can be found here:
https://www.pianobuyer.com/Resources/Piano-Brands-Profiles/Detail/ArticleId/118/Brand/YAMAHA

If you like the tone of the piano, I would not view the use of a laminated soundboard as a serious issue. Piano designer Del Fandrich published an article in a prior issue of the Piano Buyer talking about this.

What matters is the tone of the piano not whether the soundboard is laminated or solid. To be fair the soundboard is one of the factors that goes into that tone but it is the end result overall that matters.

If the tone is equally good however, you are probably better off with a laminated soundboard as it will be more stable.