HERUS: Asynchronous USB Audio 2.0, 24bit 352.8Ks/S, DXD and DSD64/128, 2.4VRMS Headphone DAC $ 390
HERUS is the smallest form-factor, audiophile quality USB to Headphone DAC from Canadian brand, Resonessence Labs.
It uses the USB Audio 2.0 Asynchronous protocol and supports DSD64 and DSD128 as well as high data rate PCM at 24bits up to 352.8Ks/S. It is a USB powered device that achieves more than 100dB of SNR, (typically 108dB) and is capable of driving 2.4V RMS, (ie 6.8V pk-to-pk) into headphones from 600 Ohms to 32 Ohms. The distortion in all cases is better than 0.005% (85dB): the measured THD+N is typically 89dB for 32 Ohms and 90dB (about 0.003%) for 600 Ohms.
HERUS is designed to operate with MS Windows, MAC OS and Linux. You may download our Thesycon USB Audio 2.0 driver to enable USB Audio 2.0 on Windows. HERUS uses the ESS 9010-2M DAC, our custom code, and our own asynchronous algorithms that run in a generic Cypress USB interface chip.
We use Resonessence designed, advanced power line processing circuits that can reliably deliver more voltage range than the USB provided 5V, and we maintain the SNR of the power supply to a degree such that HERUS exhibits well over 100dB of SNR at the headphone output. HERUS also has a very low 0.2 Ohms output impedance that prevents external noise sources coupling into the output.
All Resonessence products feature upgradable firmware and hardware and despite its physically small size, HERUS also contains Resonessence upgradable hardware and firmware.
HERUS is machined from a solid block of aluminum and is 63.5mm (2.5in) long, by 31.7mm (1.25in) wide and 19mm (0.75in) high. It has just two connectors: a USB type ‘B’ socket on one end and a TRS 1/4inch Stereo Headphone connector at the other end. HERUS, like all Resonessence products is Designed, Manufactured, Tested and Shipped in Canada.