Turbo Tuner ST-300 by Sonic Research

The Turbo Tuner ST-300 by Sonic Research is a highly precise and versatile strobe tuner designed for stringed instruments. It is available in two versions: the ST-300 Full Size and the ST-300 Mini. The ST-300 Full Size can be powered by a 9 Volt battery or an external 9 Volt DC supply, while the ST-300 Mini requires an external 9 Volt supply.

Key Features:
1. True Strobe Display: The Turbo Tuner features a true strobe display that instantly shows the slightest change in pitch.
2. Chromatic Mode: It tunes any note in the scale from C0 (16.35 Hz) to C8 (4,186.0 Hz).
3. Open Tuning Modes: In open tuning mode, the tuner shows the string number instead of the note letter. It offers five customizable modes for alternate tunings.
4. Alternate Temperaments: The tuner can be programmed for up to 5 different alternate temperaments.
5. Drop Tuning: It allows transposing all notes up to 6 semitones.
6. Compact Size: The ST-300 Full Size tuner is the same size as a typical MXR pedal, while the ST-300 Mini is even smaller.
7. Reference Pitch Adjustment: The A4 reference pitch may be set to any frequency between 300.0 Hz and 599.9 Hz in .1 Hz increments.
8. Power Supply: The ST-300 Full Size can be powered by a 9 Volt battery or an external 9 Volt DC supply. The ST-300 Mini requires an external 9 Volt supply.
9. No Battery Drain When Off: The tuner does not drain the battery when switched off, allowing the instrument to remain plugged in.
10. Power On Restore: The Turbo Tuner remembers the settings from the last time it was powered down.
11. Low Battery Indicator: It displays a message when there is about 1 hour of battery life remaining.
12. Extreme Accuracy: The internal time base of each Turbo Tuner is calibrated at the factory to +/- 1ppm (that's .0017 cents) and is guaranteed to maintain an accuracy of +/- .02 cents for the life of the product.

Specifications:
- Dimensions: Vary based on the model (ST-300 Full Size and ST-300 Mini)
- Weight: ST-300 Full Size: 247 g / 8.7 oz (including battery), ST-300 Mini: 153 g / 5.4 oz
- Temperaments: Five fully programmable temperaments
- Tuning Range: C0 (16.35 Hz) to C8 (4,186.0 Hz)
- Accuracy: +/- .02 Cents (calibrated crystal oscillator)
- Reference Pitch: A4 = 300.0 Hz to 599.9 Hz in .1 Hz increments
- Power Supply: 9 Volt DC external power, or 9 Volt Alkaline Battery (ST-300 Full Size only)
- Power Consumption: 50 mA typ.

The Turbo Tuner ST-300 is a powerful and accurate tool for musicians seeking precise tuning capabilities for their instruments.