Micro Monitor & Tuner


Triple-Function Monitor/Tuner for Guitar and Bass

Small, cool and feature-packed, BOSS’s new TU-88 is a must-have for guitar and bass players on the go. Available in black or white, it provides needle-accurate tuning, a metronome, and a headphone amp with speaker simulator for monitoring effects, including compact pedals.

Feature Packed

In addition to BOSS’s famous needle-accurate tuning, the TU-88 has lots of great extras onboard. A built-in metronome with selectable rhythms and tap-tempo is a great practice tool. The Mix Input lets you connect an iPod or other music-playback device for play along practice and jamming.

Private Monitoring

With the TU-88’s built-in headphone amp, you can plug in a set of headphones and tune in complete privacy. It’s also a great way to warm up before a show, and to verify your effects chain through headphones before letting loose through your amp.

Tuning Range
E0 (20.6 Hz) - C8 (4,186.0 Hz)
Reference Pitch
A4 (435- 446 Hz)
Tuning Accuracy
± 1 cent
Power Supply
Dry battery 6F22/6LR61 (9 V) type, AC adaptor DC 9V (PSA series; optional)
Current Draw
30 mA
Expected battery life under continuous use (carbon)
Approximately 8 hours
*This figure will vary depending on the actual conditions of use.
Dry battery 6F22 (9 V) type (carbon), Owner’s Manual, Leaflet (“USING THE UNIT SAFELY” and “IMPORTANT NOTES”), Information
Size and Weight ( including battery )
140 mm
5-9/16 inches
80 mm
3-3/16 inches
30 mm
1-3/16 inches
190 g
0 lbs. 7 oz.
*The specifications are subject to change without notice.


If you have questions about operating your BOSS product, please check our Knowledge Base for answers to the most common questions.
You can also contact our Product Support department by phone or email.
In addition, we have a library of Owner’s Manuals and Support Documents that you can download and reference.

Owner’s Manuals

Support Documents

  • BOSS Tuners Catalog 2009

    BOSS tuners are beloved by musicians around the world for their reliability, accuracy, and user friendliness. Since 1983, the TU-12 has been an industry standard. Today’s family of BOSS tuners melds the essence of the TU-12 with modern technology in a wide variety of models.