Made in Hungary, in 1959.
Mechanikai Laboratorium (ML)

It was the first self-devised modern studio machine of Mechanikai Laboratorium Company.
Tape speed: 38,1-19,05 cm/s.
Frequency response: 40 Hz- 15 kHz
"We prepared six days and nights with Laszlo Helle for the exhibition. The first demonstration stereo recording was the sound of a steam locomotive. The voice of STM-10 stereo was shocking! The stereo (three-dimensional) sound was newness in that time. It was a great success in the exhibition." -Report with Alajos Zartos, the head-constructor of ML.
(This informations are from the book: "The History of the Fabrication of Tape Recorders in Hungary" -written by Vilmos Nagy, the owner of the museum)