The B23 L is a compact power supply unit that provides 9V phantom power to the AKG MicroMic series. Two mini-XLR-F inputs (L and R) ensure optimum use for up to two microphones. Both inputs of the B23 L can be switched either to mono or stereo mode. The output is a standard 3.5mm stereo jack. Two AA batteries guarantee an average use of 30 hours. Another great feature of the B23 L is that it can be used as a small and portable mixer. Two separate volume controls allow the user to set the level of each microphone independently. Customers who want to compensate level differences between two audio sources (e.g. voice and instrument) will greatly benefit from this feature. On the rear panel of the B23 L there is the battery compartment and a metal clip for fixing the B23 L to a belt, guitar strap or the like. The B23 L is an attractive solution for customers who are looking for a small and portable power supply capable of mixing up to two audio signals in one device.