"Optical Out" - Is that ADAT or SPDIF?

[Brian]

My piano has it labeled as "Optical Out". I don't know if that's ADAT or SPDIF. How do I check? I can't buy an AD/DA Converter without knowing what format my piano is using. ADAT and SPDIF uses the same cable, but they're entirely different protocols.

[Yoozer]

It can be both. However, nobody's helped one bit if you don't tell us what brand and model piano it is. SPDIF also comes in another variant with RCA (cinch) plugs.

If it's an Alesis QS, it's ADAT.

[Brian]

It's a Yamaha Clavinova CVP-307

[Yoozer]

The way they mention in the manual that it's for CD or MD recorders leads me to believe that it's SPDIF.

ADAT carries 8 mono channels; if they would've pictured a harddisk recorder and mention the separate tracks specifically, it could've been ADAT.

There's not a big chance of breaking anything; I believe ADAT signals to an SPDIF device simply makes it do nothing as opposed to horrible loud squeals or something. Then again, that's why you have sacrificial earbud headphones.