Sonic Research Turbo Tuner ST-200 Stomp Box Strobe Tuner

Sonic Research Turbo Tuner ST-200 Stomp Box Strobe Tuner
Model: ST-200
Weight: 1,1

Sonic Research Turbo Tuner ST-200 Stomp Box Strobe Tuner

       True Strobe Display

Easy to read display instantly shows the slightest difference in pitch of the note played from the indicated note. The ring of LEDs is a true stroboscope, driven directly by the analog input signal and a precision internal frequency reference. This gives zero latency and instantly shows the slightest tuning error.

·        True Bypass / Muted Output

The output of the ST-200 is muted when the tuner is on, and when off the input signal is passed directly to the output. It is completely disconnected from all internal circuitry and the tuner puts zero load on the signal.

·        Extreme Accuracy

The internal timing generator is calibrated at the factory to maintain a precision of ±.02 cents.

·        Chromatic Mode

Permits tuning to any of the 12 notes from C0 to C8, in any temperament.

·        Open Tuning Modes

Tunes to preset or user defined tunings. In this mode the tuner only recognizes notes that are defined for the specified tuning. The tuner comes with a number of pre-defined tunings for stringed instruments. These can be edited by the user.

·        Power On Restore

The ST-200 remembers the settings for mode, drop tuning and A4 changes. No battery is necessary.

·        Flat Tuning

Lowers all pitches up to six semitones.

·        Reference Pitch Change

By default, the tuner uses A4=440Hz as the reference pitch. This can be changed in increments of .1Hz, over the range of 300.0 Hz to 599.9 Hz.

·        Temperaments

The ST-200 can operate in the equal temperament or any 12 note temperament the user desires. The ST-200 can store a total of 5 different temperaments, in addition to the equal temperament.

·        Battery or External 9 Volt Operation

The Turbo Tuner ST-200 can operate for 12 hours continuous from a standard alkaline battery. This is enough for about 1,000 tune ups. It also works with any 9 Volt adapter designed for stomp boxes.

·       Low Battery Indication

     When there is about a half an hour of battery life remaining, a low battery warning is shown on the note display every 2 minutes.


Flat Tuning

Flat tuning lowers the pitch of all notes below the regular tuning from one to six semitones. To change the number of flats, hold the FLAT button while turing the tuner on. The Flat LED will flash, and the note display will show the number of flats. Pressing the FLAT button will advance the number of flats. Pressing the CAL key will save the number of flats and return to normal operation.

When the number of flats is anything other than zero, the Flat LED will be illuminated.

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Changing the Reference Pitch

The default reference pitch is A4=440 Hz. This can be changed in .1Hz increments to any value from 300.0 Hz to 599.9 Hz.

To change the reference pitch, press the CAL button while turning the tuner on. The A4 LED will flash, and the current setting of A4 will scroll through the note display.You then press the CAL button to scroll through the current setting, and use the FLAT button to change each digit.

After the desired value has been entered, press the CAL button until the note display is blank, and press the FLAT button. The tuner will now resume normal operation.

Whenever the A4 reference is set to anything other than 440.0 Hz, the A4 LED will be illuminated.

The Clear Key

Holding down both buttons while turning on the power will have the following effect:

  • The A4 reference frequency is set to 440Hz.

Any flats are cleared.


4.4" (11.2cm) x 2.4" (6.1cm) x 1.4" (3.4cm) HxWxD


246 g / 8.7 oz (including battery)


True bypass, muted output. Zero load on signal when tuner is off. Output muted when tuner is on.

Tuning Range

C0 (16.35 Hz) to C8 (4,186.0 Hz)


+/- .02 Cents (calibrated crystal oscillator)

Reference Pitch

A4 = 300.0 Hz to 599.9 Hz in .1 Hz increments.


Input, Output (1/4") and external 9 VDC

Power Supply

9 Volt Alkaline Battery(included), or external 9 Volt DC adapter (optional).

Power Consumption

43 mA typ. Gives 12 Hour continuous operation with alkaline battery