BOSS TU-3S Chromatic Tuner for Guitar and Bass

BOSS TU-3S Chromatic Tuner

The BOSS TU-3S Chromatic Tuner delivers TU-3 tuning performance in a smaller, always-on pedalboard format without a footswitch. It provides ±1-cent accuracy, a C0 to C8 tuning range, adjustable 436 to 445 Hz reference pitch, a 21-segment LED meter, and dedicated chromatic, guitar, and bass tuning modes.

Designed for guitarists and bassists who use switching systems or need to conserve pedalboard space, the TU-3S supports seven-string guitars and six-string basses. Flat-tuning modes accommodate guitar tunings down six semitones and bass tunings down three semitones, while Cent and Stream displays provide two visual approaches to checking pitch.

High Brightness mode improves LED visibility for outdoor stages, and the Accu-Pitch Sign visually confirms when tuning is complete. The tuner operates from an optional BOSS PSA-series AC adapter rather than batteries. Its DC OUT connection can also distribute power to compatible pedals when used with the appropriate BOSS parallel power cable.

Key Features

• ±1-Cent Tuning Accuracy: Provides precise chromatic, guitar, and bass tuning across a wide instrumental pitch range.
• Compact Always-On Design: Removes the TU-3 footswitch to conserve pedalboard space and remain continuously available while powered.
• 21-Segment LED Meter: Provides a clear visual indication of pitch with selectable Cent and Stream display modes.
• High Brightness Mode: Increases meter visibility for outdoor stages and other brightly illuminated environments.
• Accu-Pitch Sign: Uses meter movement to visually confirm when the instrument reaches the correct pitch.
• Extended-Range Instrument Support: Tunes seven-string guitars and six-string basses in addition to standard instruments.
• Flat-Tuning Modes: Supports guitar tuning as much as six semitones below standard and bass tuning as much as three semitones lower.
• DC Power Distribution: The DC OUT connection can supply compatible BOSS pedals when used with suitable PSA-series power and cabling.

Technical Specifications

• Product Type: Chromatic instrument tuner
• Model: TU-3S
• Tuning Range: C0, 16.35 Hz to C8, 4186 Hz
• Reference Pitch: A4 = 436 to 445 Hz in 1 Hz steps
• Tuning Accuracy: ±1 cent
• Tuning Modes: Chromatic, Chromatic Flat x2, Guitar, Guitar Flat x2, Bass, Bass Flat x3
• Guitar Flat-Tuning Range: 1 to 6 semitones below standard pitch
• Bass Flat-Tuning Range: 1 to 3 semitones below standard pitch
• Display Modes: Cent, Stream
• Meter: 21-segment LED
• Brightness: Standard and High Brightness modes
• Accu-Pitch Sign: Supported
• Controls: Mode button, Stream/Cent button
• Indicator: Check power indicator
• Signal Path: Buffered
• Operation: Tuner remains active whenever the AC adapter is connected
• Nominal Input Level: -20 dBu
• Input Impedance: 1 megohm
• Nominal Output Level: -20 dBu
• Output Impedance: 1 kilohm
• Recommended Load Impedance: 10 kilohms or greater
• Input: 1 x 1/4" phone jack
• Output: 1 x 1/4" phone jack
• Power Input: DC IN
• Power Output: DC OUT
• Power Supply: Optional BOSS PSA-series AC adapter
• Battery Operation: Not supported
• Current Draw: 30 mA at 9V DC
• Current Draw in High Brightness Mode: 85 mA at 9V DC
• Dimensions (W x D x H): 2.9 x 3.3 x 2.2 in
• Weight: 0.5 lb
• Optional Parallel DC Cord: BOSS PCS-20A
• Manufacturer Warranty: 5 years

What's In the Box

• BOSS TU-3S Chromatic Tuner
• Parallel DC cord with 2 DC plugs
• Rubber foot
• Safety, important notes, and information leaflet