Field Report: Klotz Digital Vadis DC II

July 1, 2004

When Clear Channel Communications consolidated its Chicago broadcast facilities in 2002 and 2003, a search began for an integrated solution to tie all seven of the stations together as one technical facility. Several vendors came up with solutions, but for us the Vadis DC II from Klotz Digital stood out above all the rest.

What we were looking for was the ability to dynamically route digital and analog audio, as well as dynamically route machine control, across 28 studios that could potentially be shared by any of the seven stations. The facility was designed with clusters of four studios for each station, with several of those studios shared by everyone. A central Technical Operations Center (TOC) houses the bulk of the audio equipment, but each station's main studio is configured so it can act as a stand-alone island, and go on the air independently.

Performance at a glance
Integrated router and console design
Software-defined operation
Hardware and software modularity
End-user programmable
Expandable console work surfaces

When we reviewed the various systems, the sales staff at Klotz explained carefully that the Vadis system is a completely new concept of how to do things, and showed us exactly what their hardware was capable of doing. The full effect of that statement did not sink in until things were operational for a year, and changes needed to be made in the facility. Forget the punch tools and soldering irons, just rewrite some configuration files and the entire personality of the facility can change.

Equipment setup

The Vadis system is a versatile hardware routing system that has every cross point, button, lamp, relay and opto-isolated input defined in software. The basis of operation is time-domain multiplex (TDM) routing of digital data that is clocked serially through the system at the sample rate. That rate is defined at sample rates of 44.056kHz, 44.1kHz, 47.925kHz or 48kHz.

Hardware cards plug into mainframes handling functions such as fiber I/O (64 channels wide), AES in/out (eight stereo pairs), AD/DA (four channels) and digital signal processing (DSP). All inter-frame audio data is handled on fiber, and all supervisory control data is handled on a proprietary Ethernet network using the 802.3 protocol. External machine control is handled by Ethernet based hardware GPI boxes each capable of 32 I/O channels, or directly off the frame itself in the case of the compact audio frame, the V220.

The Vadis 880 frame is the engine behind the system.

The user interface can be a modular (hardware-based) console work surface, a virtual PC-based (touch-screen) work surface or a combination of both. Because every button and fader is defined and controlled in software, imagination is the only limitation on the configuration possibilities.

The software to accomplish all of this is a text-based programming language that is made available to the end user. Using Klotz standard syntax, the entire system can be defined to meet specific needs. The learning curve for the code is somewhat steep, but once the basics are learned it is easy to implement. Klotz Digital offers a week-long training school so that engineers in the field can modify and maintain their own facilities. Users are encouraged to attend these classes.

As for running a console on a Microsoft product, it's not a problem. A PC runs the GUI, control and routing for the attached Vadis frame. The Windows 2000 OS itself is stable, as long as it is not running MS software applications. The system architecture is designed so that shutting down anything except the Vadis frame itself does not interrupt the audio. For service of the frame, we have two levels of bypass. First, a software bypass done in the TOC with Vadis routing, and second, a total Vadis bypass by putting the station's automation system direct to air. This is used in case we want to update firmware or software in parts of the Vadis system that are common to all stations. In addition, each air studio can act as a stand-alone island, routing direct to air, in case the entire technical operations center was to go down. This is unlikely due to the multiple soft-switched fiber paths and routings designed into the system as we configured it.

The operating screen can be customized.

From the board operator's point of view the entire system acts like a standard console. The only studios that are a bit different are the voice-track rooms, which house a four-fader work surface and a touch screen. The functions of monitor switching and level control are all handled with soft keys written into the GUI. Those four-faders can be programmed on the fly to be any source in the facility if we choose. Normally we limit the jock to seeing only what he needs to see for the job at hand. If we wanted, the consoles could be day-parted so that the less experienced operators could not get into trouble. They would see only what we want them to.

The next step of development for our system will be integration of a front door intercom system to the studios. Included will be a touch screen interface, a menu driven GUI designed to be non-technical, GPI control of two-way video (externally switched) and interactive station audio monitoring. As I said, the imagination is the only limit to what can be done.

Klotz Digital

After a year's operation, the system has proven that the choice was right. When asked by a competitor what he thought of the Klotz Vadis DC II system, Market Director of Engineering Bob Fukuda said, "They will have to pry it out of my cold dead fingers, before I give this system up."

Wright is a senior studio engineer for the Clear Channel stations in Chicago.

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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