Field Report: Soundtech Lightsnake

April 1, 2007

The PC is a natural part of everything we do in radio today. There is little separation between audio, RF and IT anymore. Because of this, it's easy to find lots of audio-to-PC interfaces to make a laptop or a desktop machine a complete production facility. The units that I have seen usually provide several inputs and outputs, and offer an easy and quality alternative to a custom sound card. These are handy and have their purpose, but what if you only need to provide a single mic input?

There are mics that are built with a USB connector instead of an XLR, and they seem to work well, but many only work as a USB device. I have several dynamic mics that I like to use, and the ability to use my usual set of mics is an option that I would like to keep. To help me with this, I found an interface cable that provides what I needed: the Soundtech Lightsnake. The Lightsnake series is instrument output (guitar, bass) or mic output to USB in interface cables. The cable gets its name from the LEDs in each end of the cable.

The first challenge was opening the package. The cable is packaged for retail sale in a plastic clamshell case that is impossible to open without completely destroying it. Once opened I found the cable, a mini CD with the USB drivers and a 30-day demo DVD with Sony Acid, Sound Forge, Vegas and other audio software programs. I passed on the demo software and went straight for the cable. I didn't read the manual because printed documentation is nonexistant, which concerned me at first.

Plugging in

I tested the cable on a PC running Windows XP Pro. I plugged the cable in and Windows immediately recognized it as a USB audio device. Once the PC recognized the cable, both ends of the cable lit. It looked like everything was ready to roll. I plugged in a hand-held mic, opened an audio editor, created a new file, clicked record and saw audio on the meters. So far so good.

I opened the audio control window to check everything, and I saw that the Soundblaster card was installed, and now an additional audio device called USB Audio Device was available.

I went back to the editor and clicked play. As was to be expected, audio played back. While this isn't surprising, I was pleased that I was able to use the cable without any real installation. The cable is touted as plug and play, and it actually is.

I repeated the installation test on another PC running Windows XP with a Lynx soundcard, and the process was the same. Plug and play all the way.

Performance at a glance
16-bit 48kHz or 44.1kHz output
76.1dB THD + N
83.1dB SNR
81.6dB dynamic range
1M input impedance
Frequency response @ 48kHz sampling 20Hz to 19.2kHz
Works with Win 98 or later and Mac OS 9.0.4 or higher

The cable LEDs have a function beyond the simple light show. When the cable is ready to go, the lights are on steady. When the audio recorder is put into record, the LEDs flash. This is to show that the cable is active and functioning.

The cable itself is rather robust and measures ⅝" in diameter and is 10' long. This is much longer than is necessary for recording a voice track while sitting at the PC, but having the extra cable length may be convenient for some uses. The connectors on each end are securely attached. The XLR connector housing is a little larger than a standard XLR. The USB connector is rather beefy, but the A/D converter electronics are encased within it. The larger connector and thicker cable could present some stress to the PC's USB connector if the user is not careful. Both connectors are sealed, so there's nothing to repair if something breaks, although the XLR end could probably be replaced if needed.


The real test of the cable is in how it sounds. On the first installation, I played the audio back through a small set of powered Yamaha speakers. The audio sounded good. I could see a little dc offset on the audio editor waveform. When I listened to the audio on the second installation, which was routed through a console and over a pair of JBL speakers, I could clearly hear some underlying hiss that followed the record level setting. The noise was low, but it was noticeably higher than the mic chain feeding the console and audio editor.

With a multimeter, I noticed that pins one and three of the XLR connector are tied together, which means the audio path to the USB connector is unbalanced. This could be one source of some of the noise, although it's more likely just the audio amplifier or A/D electronics.

Look what I found

After recording several audio tracks, I decided to look at the contents of the driver CD and found that it includes a user manual. The manual is basic and contains little technical information, but there isn't too much to using the cable in the first place.

The cables are available through several online music retailers, and the instrument version is available at Target, so it's obvious that this product is geared toward the consumer market. Regardless, the cable provides an easy way to interface a mic to a PC without requiring a separate sound card. The quality is not as high as a dedicated sound card or professional mic processor chain, but the cost of this cable is also significantly less. The cable could find a suitable use for creating podcasts or capturing interviews on the go.

Weiss is director of engineering for the four Wilks radio stations in Kansas City.

Editor's note: Field Reports are an exclusive Radio magazine feature for radio broadcasters. Each report is prepared by well-qualified staff at a radio station, production facility or consulting company.

These reports are performed by the industry, for the industry. Manufacturer support is limited to providing loan equipment and to aiding the author if requested.

It is the responsibility of Radio magazine to publish the results of any device tested, positive or negative. No report should be considered an endorsement or disapproval by Radio magazine.

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