PETERSON AutoStrobe 490-ST

The Model 490-ST includes stretch tuning capabilities for enhanced tuning of string or percussion instruments, such as the piano, bass, guitar, marimba, steel pan, and others.

Only Peterson strobe tuners respond at the speed of light to display relative tuning of any audio source to 0.1 of a cent (1/1000 of a semitone) accuracy! With new AutoStrobe models like the Model 490-ST, students, technicians, and musicians at all levels can utilize automatic (hands-free) note selection for fast, accurate tuning of instruments. This feature also permits a real-time display of intonation to improve performance and listening skills while playing.


  • Wide Selection of Pre-Programmed Stretch Files - tables with optimized tunings for all piano types and sizes takes the drudgery out of piano tuning! Up to 31 additional files may be programmed by the user.
  • Automatic Note Selection
  • Automatic Image Clarity and Contrast Control - internal compensation for optimal viewing over a wide range of source pitch and volume.
  • Improved Clarity For Upper and Lower Register Notes - +2/-1 display feature shifts the strobe patterns into more visible middle ranges—bass note patterns can be displayed two octaves higher and treble note patterns can be displayed one octave lower in strobe display.
  • Easy Transposition - strobe patterns appear at the correct note for Bb, F, and Eb instruments.
  • External Input and Through Output with Mute - for in-line, silent tuning during performances.
  • Accessories - external mics, footswitches, and carry cases available.