If the CLEAN channel on the BluBOX's headphone output begins to distort very early, the level on this output is too high for the corresponding headphones. Different headphones have different volume levels. A Sennheiser HD 25, for example, is relatively loud, and some other headphones can be a good deal quieter.

Since the level of the headphone output of the BluBOX cannot be regulated, the output volume must be regulated by adjusting the input volume. To do this, the input sensitivity switch of the BluBOX is set to HIGH, and the master volume of the amplifier is adjusted so that the clip LED of the BluBOX lights up green continuously and only briefly flashes red when there are level peaks. If the headphones are too quiet, louder headphones should be used.

If the headphone level is too low, please do not turn up the CLEAN VOLUME or the MASTER VOLUME on the amp, as this will eventually start to distort.