Years ago (and I'm showing my age here) I recall a claim being made for the Klemperer LvB Missa Solemnis on Vox 11430. However, even if that was true
then, it can't come close to what is claimed here.
There is a French Wikipedia entry at:
http://fr.wikipedia.org/wiki/Disque_microsillon_inhabituel
with a Google-translation for the Trimicron entry as follows:
Developed in the mid-1970s by the firm MDR (Magnetic Disc Recording), the disc "Trimicron" enjoyed notable success, even if ephemeral. The idea was to remove the gap groove separating each turn at every turn. On average, this space corresponds to the space occupied by two grooves, and thus, the deletion of this space tripled duration engraved records (an average of 55 minutes on one side of 33 t). Initially designed for classical music lovers who could no longer having to return their 33 favorite tricks in the middle of the recorded work, the process was presented by Dr. Rabe, music lover in his spare time. For example, one can find all the Six Brandenburg Concertos on a single 33 rpm. However, this revolutionary process still suffering from a major problem: a finer engraving that involved the decline of the dynamics and the signal recorded by almost 40 percent. It was necessary to bring turntables silent and equipped with new diamonds and high performance. Discs "Triple Time TRIMICRON" being of our few days mostly in good condition, their collection of coast is increasing over time. A catalog of almost 30 TRIMICRON discs are, however, and few copies still in very good today listening state.
I had never heard of this series before and thank you for bringing it to
my attention.
Jerry
P.S. These are probably even rarer to find that those short-lived 16 2/3 rpm
discs (from Vox ?).