Use this when you don't want people to hear you tuning up. The signal will be 'on' for when the tuner is not engaged or in use, and the signal will be 'off' when the pedal is being used to tune.

Output 1 - 'Output': When this output jack is used, toggling the footswitch will turn the signal on or off.How this footswitch works is dependent on the output jack used. Footswitch 1 - 'Active/Bypass': Toggles the function of the pedal between 'on' and 'off'.Setting the number of steps or half-steps below standard tuning you may wish to tune your instrument.Button 2 - 'Mode': At first glance, this button toggles between.Button 1 - 'Stream / Cent': At first glance, this button toggles between 'Stream' and 'Cent' tuning methods, but there's a lot more functionality described below.From these previous electronic tuners we now arrive at the TU-3. The TU-12 and TU-12h were originally designed to fit in the cavity near the handle of the Boss 6-pedal-unit, the BCB-60. Prior to Boss developing the pedal form-factor, these tuners were housed conventional plastic enclosures that tuned using flat/sharp light indicators, and bouncing needles in-a-VU-meter-style presentation. The original inspiration for the TU-3 consisted of both the original TU-12 *and* TU-12h. The TU-3 Chromatic Tuner took the TU-2's existing functions and improved upon them by offering more tuning modes, and a greater calibration range. This is only mentioned because the TU-2 was itself a reimagining of the Boss TU-12h 'High Range Chromatic Tuner'. The TU-3 is an advancement on the previous pedal form-factor TU-2.

Boss chromatic tuner tu 12h