The Sound Card Problem
Using a PC sound card to interface with a professional audio system usually leads to numerous problems. The inputs and outputs are often at the wrong levels. The unbalanced interface creates ground loops that cause hum and buzz. The “EMI hurricane” within the PC case creates even more noise, and the audio quality of many sound cards is often subpar, (despite exaggerated claims) with pedestrian design and poor component quality. Although these shortcomings may tolerated by a non-technical user, they are not acceptable in a broadcast station or professional audio installation.
The USB Matchbox II Solution
Henry Engineering’s USB Matchbox II has been designed as a true professional product that solves all of these problems. It delivers impeccable audio quality, XLR connectivity, and the convenience of a simple USB connection to the computer. The heart of the USB Matchbox II is Burr Brown’s new generation phase coherent Delta Sigma 8X Oversampled codec with SpAct audio clock recovery architecture. The codec’s superb performance is further enhanced with proprietary L/C pre-filtering and edge-of-the-art analog circuitry, fine-tuned to eliminate the transient intermodulation products that plague the typical sound card. Careful attention to component selection and circuit board layout further enhance the design to yield true Audiophile performance: ultra smooth, open and transparent “un-digital” audio with rock-solid bass, crystal-clear highs, and exceptional transparency. The USB Matchbox II will sonically outperform nearly any sound card and even surpass the quality of many 24 bit systems.
For The Professional User
The USB Matchbox II’s built-in AC power supply allows operation at true professional levels with liberal headroom. MS-Windows, Mac, and Linux platforms are supported; no special driver or software is needed. The USB Matchbox II will operate with virtually any audio editing, recording, or broadcast automation software that supports a USB sound device at sample rates up to 48 kHz and 16 bit resolution.
The USB Matchbox II provides the quality and facilities that professional users require. Its dual-PLL asynchronous design permits simultaneous record and playback at different sample rates. Front panel trimmers allow precise adjustment of input and output levels. A high performance Headphone output is provided for critical monitoring. Rear panel connections include XLRs for balanced analog I/O and the AES/EBU digital output. The steel chassis provides effective RF shielding. All ICs that connect to the “outside world” are mounted in sockets.
The unit is powered with an internal AC power supply.
3 Optional mounting solutions are available
• Rack mount shelf
• Desk mount
• Wall/Cabinet mounting brackets
• Analog Input, X2 Balanced, 10K input impedance -6 to +8 dBu nom. input level
• Analog Output, X2 Balanced, 600 ohm load or higher +4 dBu nom, +24 dBu max. level
• Analog I/O Reference +4 dBu = -15 dBfs (user adjustable)
• AES/EBU Output Balanced, transformer isolated, 110 ohms
• Headphone Output 24 ohms or higher, 3.5mm stereo jack
• USB Compliance USB 1.1 or higher
• Sample Rates 32, 44.1, 48 kHz
• Bit Depth 16-Bit Delta-Sigma ADC and DAC
• O/S supported MS-Windows, Mac, Linux
• Power requirement 115 or 230 VAC, 2W, plus USB
• Physical 5.7” w x 1.7”h x 6.0”d 3 lbs