The Koszalin from XAOC Devices is a completely digital frequency shifter with two inputs and four outputs. Even though the module is specialized in changing frequencies, it has nothing in common with a pitch shifter in the result. The fact that Koszalin's signal path is stereo is a clear unique selling point for this module. Added to this is the ability to perform frequency shifts in three carefully scaled ranges (+/- 50Hz / 500Hz / 5kHz) using exponential and linear Thru-Zero modulation simultaneously. Frequency shifting results in a linear shift of the signal spectrum, producing all kinds of atonal sounds. Several stereo feedback topologies are provided with signal density and feedback content leading to spectacular stereo barber pole effects, among others. Thru-Zero modulation allows the input to be used as an FM operator.