« The FiiO CP13’s audio circuitry is said to use analog devices, from the magnetic tape head to the signal amplification. The motor is powered by a high-voltage 4.2V power supply, which FiiO says is “more than the 1.8V or 3V typically found in portable cassette players.” This power supply works in tandem with a custom motor-speed stabilization circuit, which increases the drag on the motor to ensure stable movement speeds, as well as manage pitch changes and enable the CP13 to handle additional/other cassette types. The FiiO CP13 employs a differential circuit for balanced acquisition of signals from the custom head.«