The pre-in input also offers the option to use the Cayin CS-300A as a pure power amplifier. Different taps for 4, 8 and 16 ohms allow for adjusting to the speakers in use. An output transformer specially designed for this single-ended amplifier with separate winding taps for the headphone output additionally makes the CS-300A ready for operation with headphones.

User can adjust the bias of the 300B tubes with the integrated display and a two-stage switch for individual adjustment of the negative feedback are also built into the amp.

The Cayin CS-300A is hand-built with point-to-point wiring. A soft-start circuit to protect the amplifier is said to provide longer life for the tubes as well as other sensitive components. In addition, Cayin uses high-voltage fuses to protect the remaining components in the event of a tube failure. All functions can be controlled via the included remote control, which comes in a metal housing.