It seems that this is not possible even with the latest Kawai models.

It seems to depend. I just had a look at the manual of your piano. Yours has indeed no line in, while Tequilas has. Odd at this pricepoint.

The CA51 doesn't support USB audio since it's from 2009.

Just connect your laptops headphone output to the line input of your CA51.
Turn off "local control" in your CA51 to prevent the piano from using the in-built sound too.

I have the same problem with my CA17 de 2015 for which I have not found a way for the Pianoteq sound to go from my laptop to the internal Onkyo speakers of the CA17 while I play. It seems that this is not possible even with the latest Kawai models. So I plugged in the Multimedia iLoud Micro Monitors. But the result is not satisfactory and after the sound of the headphones which is by far the best, that of the internal loudspeakers remains much more realistic than the IK iLoud whatever the Pianoteq sound used.

Tom, I directly record on Pianoteq, so I only want to listen through the CA51 speaker, so for reference and to compare the Kawai internal song (that I like) with the Pianoteq Sound. I'd like to attach an image with my settings, but I don't know why, it's impossible.

Zaskar, I think the problem could be just the supporting of the USB, as you say. By the way, I found on internet some Kawai drivers, and my PC sees my keyboard, but does not send the playing to it.

Just connect your laptops headphone output to the line input of your CA51.
Turn off "local control" in your CA51 to prevent the piano from using the in-built sound too.

Hi to all!

Please, I need help about a question on listening Pianoteq on my Digital Piano.
I have a Kawai CA51, and I connected to my Laptop (with WIN 10), via USB, so I can record my playing. After having recorded a piece, I'm not able to listen it through my Kawai, but only through the speakers of the Laptop.

I tryed all settings but it seems impossible. Is it really impossible, or may be I'm wrong with the settings? Thank you!

Tequila

Well, since you recorded your playing successfully, your USB connection is working. So the recording is in your recording software (DAW). I don't believe your issue is with PianoTeq software at all. Once you get your playing recorded, the recording software (DAW) controls what device it plays back to. Check the configuration in the inputs/outputs section of your recording software (DAW) configuration and you should see an ouput option for your keyboard. Right now the output of your software (DAW) is set to play out of the sound card/speakers. Your software should show your keyboard as an output option. Select it and you should be good to go.

Not knowing what software (DAW) you are using, I can't be more specific. If you want to tell us what software (DAW) you are using, I am confident someone here will be able to tell you exactly where to look to get the output redirected to the keyboard instead of the sound card/speakers.

If you are recording directly into Pianoteq and not into a separate software (DAW) post a copy of your "Devices" page in the "Edit" "Prefrences" window.

Please, I need help about a question on listening Pianoteq on my Digital Piano.
I have a Kawai CA51, and I connected to my Laptop (with WIN 10), via USB, so I can record my playing. After having recorded a piece, I'm not able to listen it through my Kawai, but only through the speakers of the Laptop.

I tryed all settings but it seems impossible. Is it really impossible, or may be I'm wrong with the settings? Thank you!

Tequila