No, I haven't and I think it is not necessary anymore. I found the problems.
Took me half a day but never mind, because I know my instrument better.
Later on - some more tests to do - I will post the answers.

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drdalet

And the winner is ......

Yes, I found the answers at last.
Simple, really - but isn't everything easy if you know the answers.
1.
For the guitar change: Autorevoice was ON. As soon as I turned that off, it was OK. Autorevoice isn't saved by registrations or anything, so if any instrument is different when playing a sequencersong, autorevoice is ON. Turn it off and it is OK. Apparently autorevoice doesn't apply to the saved styles, or you must apply it and save it as a userstyle.
2.
Why does the Tyros have 6 DSP chips and the PSR3K 4? Maybe because of this...
when the recording of the style (and me playing) was done, I played the song back. I suddenly noticed that the Start/Stop button of the Style control started flashing again. I stopped and turned everything off. But still the reverb was gone.
I made a new recording and when that was done I switched off all the buttons in the style control and then played the song.
The reverb was back.
Now if I wanted the reverb go away again I simply turned on the style control buttons and .... the reverb was gone again.

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drdalet