Cayin RU7

All audio formats are passed as DSD through RU7's precise 1-bit decode. Cayin returns to Sony's Scarlet Book SACD revolution of the 1990s and elevates that conversion philosophy with modern mobile dongle hardware.

RU7's highlight is its 1-bit decoder, converting all PCM files to quad-rate DSD first via DSP logic, while letting native DSD material flow on to the 128 discrete resistors in its DAC – in actuality a simple analog low-pass filter.

There's zero error at the point of conversion in a 1-bit DAC. There, Cayin relies on Pulse-Density Modulation (PDM)'s total accuracy, and sheer ease of decoding.

The pitch for DSD's 1-bit conversion is digital at its simplest and closest point to analog – level represented only either as a 1 or a 0, switching on or off. To achieve analog, the bitstream is simply low-pass filtered.

Cayin's all-to-DSD discrete DAC is accurate ... and also elegant, breakthrough and historic in personal audio. It draws inspiration from the illustrious halls of Hi-Fi, where each EMM Labs, Nagra Audio, Playback Designs, PS Audio and of course, N7's, 1-bit DAC release has been greeted with accolades and fanfare.

RU7's discrete proprietary tech immediately differentiates itself from commercial DAC chips, where IC packages are often too small to perform an ideal 1-bit conversion. RU7 also avoids the errors of dynamic element matching inherent to 2-7 bit delta-sigma decoders.

The decoded analog goes through Cayin's specially designed resistor-based analog volume control for perfect channel matching at any level – facilitating that very special 1-bit discrete DSD decode and importantly preserving your music's true dynamic range resolution.

A series resistor operates with shunts as voltage dividers in tandem with relays, to maintain near-perfect resolution of your music and a signal-to-noise ratio of over 110 dB. A totally novel volume solution has made this feat possible on a USB-powered dongle DAC.

Cayin differentiates RU7 from RU6 in offering the former a line-out option whereby the volume control is bypassed for a fixed voltage out, perfect for listening into motor stereo systems as well as handy and portable personal speakers. 

Meanwhile, RU7's 400mW output power is doubled compared to RU6's, such that this DSD DAC is capable of transferring all its forward-thinking fidelity into your prized transducers. Never fear for leaving your reference gear behind for Cayin's latest and greatest every-day carry. 

There ends the list of exploits worthy of celebrating Cayin's 30th anniversary in arguably more ambitious a way than even N7 offered. Check out the rest of Cayin's gear here, or view our other USB dongle DACs here.