Found on eBay, listed yesterday auction ends 7th Sept 8pm (UK). I dont recall hearing of any Stockhausen signed stuff before so this could be quite a rarity.
I loaned this synth to Stockhausen for a series of performances of the opera 'Donnerstag Aus Licht' at the Royal Opera House, Covent Garden in 1985.
After the performances ended, I asked Stockhausen to autograph the synth for me.
Dedication reads 'For another FESTIVAL, David? I'm with you! Stockhausen Oct. 1st, 1985'. Unfortunately the pen wasn't a very good contrast with the black surface of the synth, but the writing is clearly readable to the eye.
The synth works but will need a thorough service. Currently, the notes do not finish properly and some of the keys are uneven in height.
The Random S/H switch is broken but does function.
Regarding certification of the autograph, I will give the winning bidder a signed letter stating the authenticity of the autograph, on request.
Since this is a true collector's item, I am opening the bidding at £99 and I trust that it will find its true value in the auction.