A developer unit for developing a latent image recorded on an image receiving member with marking particles, to form a developed image, including: a donor member spaced from the image receiving member and adapted to transport marking particles to a development zone adjacent the image receiving member; a donor voltage supply for electrically biasing said donor member, said donor voltage supply having a donor frequency at a first phase; an electrode positioned in the development zone between the image receiving member and the donor member; an electrode voltage supply for electrically biasing said electrode during a developing operation with an alternating voltage to detach marking particles from said donor member, forming a cloud of marking particles in the development zone, and developing the latent image with marking particles from the cloud, said electrode voltage supply uses frequency generation of the donor AC and wire AC modulation frequencies by integer division of the wire AC oscillator thereby minimizing the electrical energy in the frequency spectrum below the modulation frequency that can result in undesirable copy banding.