The BR-600 uses a digital encoder to store and process incoming audio signals, so it's especially important to avoid overloading the channel. Analog clipping produces a warm distortion, similar to a guitar amp, which can sometimes be desirable. Digital clipping, on the other hand, produces a harsh, abrasive burst of white noise. Err on the side of caution when setting the input gain. Watch the input meter and play the instrument; it should be just touching the red area on the meter. Turn the input gain control down by roughly 2 decibels, and compensate the volume on the instrument. This will provide a safeguard against clipping, and will provide some extra headroom when mixing, allowing you to adjust the instrument volume over a wider range.
You can access the instrument tuner on the BR-600 at any time by pressing the "Tuner" button. By default, the tuner uses 440Hz as a reference point for the "A" note. When playing with other musicians, who may tune slightly higher or lower, the tiny tuning discrepancies can sound jarring and unpleasant. You can adjust the reference point of the tuner to match the musicians or backing track with which you are playing. Engage the tuner by pressing the "Tuner" button and turn the "TIME/VALUE" dial to set the reference frequency. It can be set anywhere from 435 to 445Hz.
Several features allow you to use the BR-600 as a practice tool, as well as a recording device. Along with the phrase trainer, that allows the user to slow down tricky phrases, the "Center Cancel" function mutes the center channel of an audio input source. This usually has the effect of removing the vocal and lead instrument parts, allowing you to practice what you have learned over the original song, without the distraction of the original vocal or instrument part. To engage Center Cancel, press the "Phrase Trainer" button, and use the arrow keys to navigate to the screen titled "Center Cancel." Turn the "TIME/VALUE" dial to toggle the function on and off.
You can route external instruments directly through the BR-600, negating the need for an separate audio mixer. Connect the output of the external device to the "Line In" input on the BR-600. Connect the BR-600 output to the amplifier or speakers as normal. Press the "Utility" key, and use the cursor arrows to navigate to the "SYS" menu. Press "Enter." Within the SYS menu, use the cursor keys to navigate to the "Sub Mixer" option, and turn the "TIME/VALUE" to set it to "ON." The external device signal will be combined with the BR-600 output and routed to the speakers.