Resonessence Herus+ USB DAC Headphone Amplifier

HERUS+ is Reseonnessence Labs smallest form-factor, audiophile quality USB to Headphone DAC. 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.

The HERUS+ is our latest version of HERUS, it meets all the specifications of the HERUS but now includes a user selectable, on-the-fly, choice of two up-sampling filters.
The first custom up-sampling filter the Apodizing Filter, the second is the Minimum Phase IIR filter. Please refer to our note on Digital Filters for more details.

Here is how it works: just plug the HERUS+ into your music source; IPad, IPhone, Android, MSWindows etc, and HERUS+ is recognized and powered up.

• HERUS+ looks and behaves just like the HERUS at power up. But unlike the regular HERUS, HERUS+ has a slightly raised “R” logo. Gently press and release the logo and the color will switch from Blue to Magenta. You have just engaged the first alternate up-sampling Apodizing filter. Press and release again, the logo remains Magenta, but the second up-sampling filter, the Minimum Phase IIR, is now engaged. Press and release a third time and the logo goes back to Blue, indicating you are now back to the nominal un-specialized up-sampling filter.
• In any filter setting press and hold the logo. After a few seconds the LED goes out. This does not change the filter setting, rather it puts the HERUS+ into a lower power state to help preserve your battery. Press and hold again and the LED lights, the HERUS+ has returned to normal power mode at the same filter setting that was engaged at power down
• Please note: HERUS+ needs the latest USB driver – check you downloaded the latest one

HERUS ________________________________________

HERUS+ is designed to operate with MS Windows, MAC OS and Linux. You may download custom Thesycon USB Audio 2.0 drivers to enable USB Audio 2.0 on Windows. HERUS uses the amazing ESS 9010-2M DAC, custom code, and custom asynchronous algorithms that run in a generic Cypress USB interface chip.

The Herus utilises advanced power line processing circuits that can reliably deliver more voltage range than the USB provided 5V, and 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 are Designed, Manufactured, Tested in Canada.