Cayin C9

C9 is a fully-balanced, truly differential amplifier built upon the essentials establishing a device as basically thoroughly engineered.

READ ALSO The full blow-by-blow story of C9's technical innovations

A high operating voltage of more than eight volts and a reliance on discrete parts for over 90 per cent of the design means C9 is not only capable of putting out over 4 watts per channel, but also ensuring it is the cleanest, most linear kind of signal possible.

Achieving 125dB of signal-to-noise ratio would not have been otherwise possible in a discrete design, with all the benefits that brings, without exacting layout. The input section exists on the popular Nutube. C9's dual timbre circuit revolves around two of Korg's fluorescent triodes or toggled solid-state FETs, the philosophical transistor alternative.

READ ALSO C9 blurs the line with desktop amplifiers

The delicate input signal is then passed to a discrete solid-state output stage that can be switched between working in pure Class A mode or Class AB. Built with individual transistors of Cayin's choosing allows great control over tuning and an innately linear open-loop circuit, with minimal negative feedback, to be fashioned, while producing genuine current for demanding headphone loads.

C9 is a brute in ballet shoes, confirmed by the big volume pot controlling dual precise MUSES resistor ladder attenuator parts occurring after the driver stage, kept far from the input signal for maximum integrity. 

Line outputs from Cayin's own N7, HiBy Music's R6III plus R2R RS6, and iBasso Audio's DX320 will never be better pampered than via C9. Use it in a mobile stack acting as the platform for Hedd's HEDDphone® – absolutely recommended, says Ear Fidelity – MYSPHERE 3.2, Rosson Audio Designs, plus almost any ABYSS or HIFIMAN, to shine.

"And while DAPs come and go", Twister6 believes "C9 should last you a while to enhance any source you pair it up with". Headfonia say it "should really be the first amp to look at to get four completely different sound signatures that's simply impressive".

See how Cayin's design chops translate to their desktop amplifier offerings here, or view our other DAC and amplifier offerings here.