Perreaux Audiant DP32

Pre-amp with both digital and analogue inputs

Digital Inputs:	1 USB (asynchronous 24/192) 1 AES/EBU (XLR) 2 Coaxial (RCA) 2 Optical (Toslink)
Digital to Analogue Converter:	ESS Technology Sabre³² Reference ES9018 32-bit DAC
Input Word Length (maximum):	32-bit (AES/EBU, Coaxial, Optical) 24-bit (USB)
Input Sample Rate (maximum):	192kHz (all inputs)
Analogue Inputs:	1 Balanced/Unbalanced (selectable) 1 Unbalanced Line/Home Theatre (selectable)

Website: Perreaux
Price: $2.895

Audioquest DragonFly USB Digital-Audio Converter

Capabilities:
• Drives headphones directly
• Variable output drives powered speakers or a power amplifier
• Fixed output feeds preamp or AV receiver
Features:
• 64-position analog volume control
• Accepts music files up to 24-bit/96kHz resolution
• Asynchronous Class 1 USB data transfer using the Streamlength protocol
• Direct-coupled circuitry from the ESS Sabre DAC chip through the analog volume control and output analog driver section
• Dual Master Clocks are used to minimize the amount of jitter present in the DAC circuitry

Website Audioquest
Price:  € 249,00

M2Tech hiFace Two USB to SPDIF converter

The biggest news is probably that M2Tech decided not to use their proprietary drivers but to using the native mode USB audio drives of the operating system.
It is UAC1 and UAC2 compliant so will work out of the box with Win, OSX and Linux.
For > 96 kHz you need a driver on Win as Win is not UAC2 compliant.
The receiver is by XMOS and the driver by Thesycon.

• Input 1 x USB A type male
• Output 1 x RCA or BNC female
• Input USB 2.0 Audio Format with aAsynchronous synchronazation 
• Output S/PDIF Stereo Digital Audio Format
• Sampling Frequency: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4khZ, 192kHz
• Resolution 16 up to 24 bit
• Dimensions 10.2(d) x 2.2(h) x 2(w) cm
• Power Supply 5V DC from USB bus
• Weight 50gr approx.

M2Tech hiFace 2 
Price: US$ 185