Abstract: The invention is an in-line voltage transformer. The invention converts input voltage from 9 volts to the selected output voltage. The output voltage options are 12, 18 and 24 volts. Thus allowing various signal processor or effects (requiring different voltages) to be powered from the same voltage source. The invention works in conjunction with a digital 12 volt power supply. The input voltage (9V) passes through a filter comprised of two capacitors C1 (1 ?F) for low frequencies and C2 (1 ?F) for high frequencies. The current then goes into a constant frequency (1.2 MHz) current mode boost switching regulator controlled by U1. The VC pin on U1 provides loop frequency compensation [comprised of C5 (100 pF), C7 (6800 pF) and R4 (6.8K 1%)]. This compensation reduces the output voltage ripple. U1 uses L1 (high frequency 10 ?H inductor) and D1 (low drop, high frequency schottky diode) to step the voltage up.