Philippe Guillaume wrote:

Update done right now, see https://www.modartt.com/pianoteq_changes

I'm waiting for the ios update (always 9.1.0 on app store).
Soon I hope...

Yes, should be there very soon.

Update done right now, see https://www.modartt.com/pianoteq_changes

I'm waiting for the ios update (always 9.1.0 on app store).
Soon I hope...

In all the Blüthner presets the keys B0, C1, C#1 create a weird double tone.
I can clearly hear some additional higher tone especially when playing C#1.
Anyone experiencing the same?

This "double tone" you mention is produced by the longitudinal modes of the string. They can be heard on all pianos, with variable intensity and pitch. The fundamental frequency of this mode is usually located between the 13th and the 15th partial of the transverse mode (the "normal" modes). These longitudinal modes are part of the "signature" of the instrument.

One hears it indeed very clearly on the notes you mention. If you have the PRO version, you can reduce them on the Blüthner grand by reducing partial #14 (and possibly #28, #41,  #52) on notes B0, C1, C#1.

EDIT: this is to be done in Note Edit > Spectrum Profile: first select/play the note to be modified, then chose the partials (overtones) to be reduced.

In all the Blüthner presets the keys B0, C1, C#1 create a weird double tone.
I can clearly hear some additional higher tone especially when playing C#1.
Anyone experiencing the same?

Yep that would be the aliquot, the Bluthners particularly prominent duplex system.

Reduce duplex resonance to match your liking. In the pro version you can do this per note