Single ended 300B tube integrated amplifier in pure class A circuit

The tube amplifier Cayin CS-300A is a rarity for special connoisseurs. It builds on the sonically unrivaled 300B output tubes. The two directly heated triodes are powered in a single-ended configuration by a 6SL7 voltage gain stage followed by a 6SN7 driver stage. Two GZ34 tubes are responsible for the channel-separated high-voltage rectification. This arrangement ensures a musically fluid sound with excellent detail resolution.

With the CS-300A, Cayin wanted to create a particularly musical integrated amplifier that, despite the puristic single-ended circuit, achieves 8 watts RMS per channel, which helps high-efficiency loudspeakers to produce an enormously harmonious, lively sound with body and expressiveness.

The pre-in input offers the possibility of using the Cayin CS-300A as a pure power amplifier. Various taps for 4, 8 and 16 ohms enable optimal adjustment of the loudspeakers used.

An output transformer specially developed for this single-ended amplifier with separate winding taps for the headphone output makes the CS-300A compatible for operation with most high-quality headphones.

Cayin has also ensured constant performance over long periods of time. Therefore, the user has an integrated measuring instrument for the precise bias adjustment of the 300B tubes. There is also a two-stage switch on the massive aluminum front panel for individual adjustment of the negative feedback . In the “0 dB” position, the sound is smooth and open, with lots of detail, while at “-3 dB” the reproduction is clear and sharp.

The Cayin CS-300A is built by hand with the finest point-to-point cabling.

A soft-start circuit to protect the amplifier ensures a longer service life for the tubes and the 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 with the included remote control in the easy-to-grip metal housing.