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electronic MUSICIAN


By Zack Price | September 1, 1999

Let me say this right up front: I prefer using multichannel digital-only audio cards in my work, and that typically means (almost by default) a card with 8-channel Lightpipe optical I/O. I realize that this option can be more expensive than using prepackaged multichannel cards with dedicated breakout boxes, but digital-only audio cards offer some distinct advantages. First, they can interface with a wide variety of compatible outboard components, such as MDMs, digital mixers, multichannel A/D/A converters, synthesizers, and samplers. Second, you can use long, easily replaceable optical cables to run between the card and the external devices. This lets you use cables that are optically isolated, thereby avoiding ground loops, and the comparatively greater cable lengths simplify the placement of outboard gear in relation to the computer and other studio equip- ment.

Currently, most manufacturers of multichannel digital-only cards offer products that are limited to providing Lightpipe connections for transferring digital audio between the computer and outboard devices. However, Frontier Design Group has taken that design concept to the next level with its powerful new Dakota card. It provides 18-channel digital audio capability (16 ADAT and 2 S/PDIF), in addition to a variety of other MIDI and synchronization features. Moreover, Frontier also makes a line of optional equipment-including the versatile Tango24 multichannel A/D/A converter-that can make the Dakota the hub of a powerful desktop music production system.

THE SCENIC ROUTEThe Dakota comes in the form of a short PCI card configured with two optical inputs and two optical outputs for its 16 ADAT-compatible digital audio channels. Either pair of optical jacks can be switched to optical S/PDIF from within the Dakota's software control panel (see Fig. 1). This allows you to connect DAT decks and CD and MiniDisc players, as well as some synthesizers and samplers, directly to the Dakota card. If you need both pairs of optical jacks for 16-channel operation (or if you just need more channels to work with), you can add Frontier's Montana daughtercard to your system (see the sidebar "Montana Wildhack").

A 15-pin connector on the Dakota's faceplate connects to a breakout cable for electrical S/PDIF (coaxial) I/O, which is switchable to AES/EBU from within the control panel. (You'll also need to use properly wired cables between any AES/EBU device and the RCA jacks of the Dakota card.) The breakout cable also includes a 9-pin ADAT-sync input jack. This turns your computer into the last slave device in an ADAT chain so that you can run your digital audio software in sync with your ADAT-compatible MDMs from the master device in the chain.

An 8-pin connector for MIDI I/O is also provided on the faceplate. You can connect the included breakout cable with the two pairs of MIDI Ins and Outs for a total of 32 MIDI channels. Alternatively, you can connect Frontier's Sierra 8 5 8 MIDI interface/patch bay to this jack for 128 MIDI channels (see the sidebar "High Sierra").

The Dakota also contains two internal connectors. The first is a digital-audio input that connects to the digital outputs of compatible CD-ROM drives for digitally transferring sound in real time to appropriate audio programs. The second connector is an internal 40-pin header that links the Dakota to the optional Montana daughtercard for expanding its audio and sync capabilities.

TWO TO TANGOBecause the Dakota is a digital-only card, you must employ outboard devices to record and play analog audio through the card. If you plan only to transfer tracks between your ADATs and the Dakota, then your setup is complete with just the card. However, you can't use an ADAT as a front-end device if you need to overdub individual tracks, because a single ADAT can't be used for both A/D and D/A at the same time; the analog/digital input selection affects all eight channels at once. Fortunately, Frontier provides an affordable 8-channel, 24-bit A/D/A converter in the Tango24. (Frontier offers a special package price of $1,149 for the Dakota/Tango24 bundle.)

The Tango24 is a single-unit rack-mount device with two sets of balanced 11/44-inch TRS jacks (8 in/8 out). These are set at the factory to +4 dBu, but you can switch each connector individually to -10 dBV (consumer line-level) by removing the unit's cover and setting a jumper for each jack. Although physically altering the settings can be tedious, it does offer excellent control over the Tango24's inputs and outputs.

For example, you can set the inputs to -10 dBV and the outputs to +4 dBu. This configuration is ideal for use with mixers on which the channel inserts can also be used as direct unbalanced outputs. You can then monitor incoming audio on separate balanced channels. Likewise, any combination of inputs and outputs can be set to +4 dBu or -10 dBV. For instance, you can set input channels 1 through 4 to -10 dBV and input channels 5 through 8 to +4 dBu; output channels 1 through 6 can be set to +4 dBu, with output channels 7 and 8 set to -10 dBV. In short, the Tango24's analog I/O can be configured to suit your needs.

The unit also contains three optical ports: in, out, and thru. The in and out jacks, naturally enough, receive and send 8-channel digital audio data. The thru port transmits a copy of the incoming audio data to another device in much the same way as a MIDI Thru port. For instance, you can route the Tango24's thru port to an ADAT digital input to make a simultaneous tape backup while a session is in progress. And because the optical thru port transmits a copy of the digital audio data, you can use the Tango24 as an extension device to send digital audio twice as far as the normal limit of 10 meters (approximately 33 feet). I'm not sure that too many people would need to send eight channels of digital audio some 66 feet, but it never hurts to have that ability.

The Tango24 also supports word-clock in and out on 75-ohm coaxial cables with BNC connectors. The word-clock input can be used as the Tango24's clock source when selected by the clock-source switches on its front panel (more details in a moment). The word-clock output is always driven by the Tango24's clock system with a frequency equal to the sample rate. You can use the word-clock input to sync to an external device or to slave to another Tango24 that is acting as the master clock device. In fact, the user guide illustrates several methods for using either the Dakota or the Tango24 as the master clock in the system.

FACE THE FACEThe Tango24's front panel provides a variety of toggle switches and informative status lights. Two switches on the left let you select the sampling rate (44.1 or 48 kHz) and the clock source (word-clock input, ADAT Optical input, or internal). Next to the Clock Source switch, the Clock Status indicator light glows steadily when the clock source is stable and blinks when the external clock source is outside the Tango24's frequency-locking range. The light also blinks when there are other clocking errors, such as an incorrect format.

The Optical Input indicator shows the status of the ADAT Optical input signal. It glows steadily when the input is valid and locked to the clock system. When the light blinks slowly, it means that the optical input is valid but is not locked to the Tango24 clock system. Most often, this occurs because the Tango24's optical input is based on a different clock source and is "slipping." (For example, the Tango24 may be receiving digital audio data at 48 kHz when its own sample frequency is set to 44.1 kHz.) You can confirm this by viewing the Clock/Device Status tab in the Dakota's control panel. Figure 1 shows how the tab appears when the digital audio data comes in at a rate that is different from the indicated settings.

When the Optical Input light blinks quickly, the data stream itself has errors. This usually happens when the Tango24 is not receiving ADAT Optical format data-because, for example, you accidentally routed two-channel S/PDIF digital audio through the optical ports of the Dakota or Montana card to the Tango24.

Three rows of eight LEDs serve as either input or output level meters, depending on how you set the neighboring Meters switch. The lights in the bottom row, labeled Signal, glow green whenever a signal is present. The intensity of the lights varies in proportion to the signal strength. The middle row of yellow lights indicates when the signal is within 3 dB of full-scale digital signal (0 dB). These lights remain lit for about half a second unless the signal stays constantly within 3 dB. The red LEDs in the top row, labeled Clip, light up when the signal is within 0.002 dB of full scale. When metering outputs, these LEDs remain lit for about half a second. When metering inputs, however, the clip indicators stay lit until you reset them by toggling the Meters switch to Output and then back to Input.

The Tango24's power is supplied by a hefty lump-in-the-line AC adapter. There's no on/off switch, but you can tell that the Tango24 is powered up when the green power indicator on the left is lit.

The Tango24 looks pretty cool when all its LEDs are glowing in the dark, but how does it sound? In a word, great! Though I performed no bench tests to confirm or disprove the unit's specs, I did record and play back a variety of audio material that I am familiar with. The Tango24's balanced analog and optical digital I/O made for very clean recordings. In fact, I felt comfortable enough with its quality that I used it in recording sessions for a client who uses both acoustic and electronic instruments in his work.

CONTROL FREAKVersion 2.0 of the Dakota control panel installs drivers for Windows 95 and 98, along with ASIO 2.0 drivers for use with Steinberg's Cubase VST and other ASIO-enabled applications. The Dakota 2.0 driver supports sample-accurate I/O using Syntrillium Cool Edit Pro 1.2 (the SE version of which is included in the Dakota package). Unfortunately, there are no DirectX drivers for the Dakota at this time, although a Frontier spokesman stated that the company is actively developing them. I hope it does, because many software synthesizers and other products-most notably NemeSys GigaSampler-use DirectX.

The Dakota control panel itself is now accessible from the Windows 95/98 Taskbar. When you right-click on its icon, you see a list of the tabs in the control panel (Clock/Device Status, Timecode, Patchbay, and System). When you click on a selected tab name, the control panel opens with that tab showing. It may not seem like much, but it's a handy time-saver.

The System tab displays the current Dakota software version as well as information on contacting Frontier Design Group. It also has a MIDI mode section for matching the MIDI I/O to the device being used: 2 5 2 when using the supplied MIDI breakout cable, or 8 5 8 when connected to the Sierra MIDI interface.

The Patchbay tab lets you route any input to any output of the Dakota or the Montana daughtercard (see Fig. 2). Furthermore, you can route an input to more than one output. For example, I have routed the inputs of Optical Port A directly to its outputs. I have also routed each channel in Optical Port A to selected individual channels of the other three optical ports. This lets me monitor the eight incoming channels and send a copy of each channel to other devices in the system. You could consider this feature a kind of simplified software version of an Alesis BRC. Best of all, you can save each patch-bay setup for easy recall.

The Clock/Device Status tab is where you select the clock source for the Dakota. If you're using the Dakota as the master clock, you set the clock source to Internal. The Dakota also receives clock information from a variety of sources, depending on the types of devices you have in your system. It can accept ADAT sync input from an external ADAT, for example, and it also accepts SMPTE/MTC if you have the Sierra MIDI interface connected to the Dakota.

With the Montana daughtercard installed, the Dakota can receive video sync or word clock. When the Digital In source is selected, the Dakota derives its clock source through whichever optical or coaxial inputs you select. For instance, you can use the Tango24's clock through its optical jack, or use the digital output of a DAT deck connected to the coaxial input on the Dakota. When Varispeed is selected, you can adjust the sample rate with the Varispeed slider. This option is useful if you need to pull down the sample rate to match the frame rate of some types of video decks. (For more on pulldown, check out "Square One: Picture Perfect Sound" on p. 96.)

The Dakota control panel's Digital Input Status section also displays the audio input status, mappings from physical inputs to logical inputs, and channel indicators. Each optical input of the Dakota and Montana (along with the coaxial input) has three indicator "lights." (The indicators for the Montana are always present, even when the card is not installed.) The left light indicates if there is an active input signal, and the middle light shows whether a valid digital audio format is present.

The right light is the Slip indicator. It appears green when the Dakota is locked to an incoming audio clock. If it turns red, it means that the Dakota's sample rate is different from the incoming audio clock. If the Dakota's rate is almost the same but not perfectly locked, the Slip indicator may flash red periodically. A slash will also appear across the green indicator until you click the Clear Errors button.

The Actual reading in the Sample Rate section can show you whether the current clock source is inactive or unstable. For example, if you've selected Digital In-S/PDIF as the Dakota clock source but your DAT machine is also set to digital input, then neither device is acting as a master (each is trying to lock to digital input from the other); in this case, the Dakota clock system will spin down to its lowest frequency. Switching the DAT back to analog input solves the problem, and you'll see the actual sample rate settle in to the proper 44.1 or 48 kHz.

By default, the Dakota's physical inputs are mapped directly to logical devices. For instance, Optical Port A maps to Logical Device channels A1 through A8, Optical Port B maps to Logical Device channels B1 through B8, and Coax maps to S1:2 (S/PDIF). Device S1:2, however, can come from any physical input. Using the drop-down box next to the device, you can choose any of the four optical inputs, the coaxial (RCA) input, or the CD-ROM; the physical-to-logical mapping lines automatically change to reflect the input status.

The Digital Output Status indicator simply shows which output channels are active along with the mapping from logical output devices to physical outputs. Although the stereo S/PDIF stream is always present on the Dakota's coaxial output, it is also possible to route S/PDIF to any of the four optical outputs: just click on the button next to the corresponding optical output, and it changes from 8-channel to 2-channel mode. Similarly, the logical-to-physical mapped lines automatically change to reflect the output status.

TIME IS ON MY SIDEThe Timecode tab is one of the most important features of the Dakota card. It offers a choice of several time-code sources, so there is bound to be a method of synchronization that you can use. Typically, the time-code source is set to Internal so that the PC's applications can control time-code generation. If ADAT Sync In is chosen, the Dakota automatically converts to MIDI Time Code. That's because most recording/playback software can receive and follow only MIDI Time Code. (It's the only form of time code in the Windows standard interface.) To receive MTC from a MIDI input, select the MTC Port option and the appropriate port number (1 or 2 if you are using the Dakota's two-In/two-Out MIDI cable).

By far the most interesting Timecode Source selection is the SoDA Channel option. SoDA stands for "SMPTE on Digital Audio," and with this option you can receive SMPTE time code through any Dakota (or Montana) digital audio input. Just connect a SMPTE time-code source to an A/D converter (such as the Tango24) and then to the desired Dakota or Montana digital audio input. Next, set Timecode Source to SoDA Channel, and then choose the appropriate input channel from the adjacent selection box.

To use SoDA for sending time code from a digital audio output, you simply select the SoDA Channel box from the Timecode Destinations section; then choose the desired output channel and set the output level of the SoDA channel signal.

If you use the SoDA Channel input and output options to synchronize the Dakota to a multitrack analog tape deck, you'll probably need to stripe the tape first. That's easy enough with the Dakota's Manual Stripe to SMPTE/MTC feature.

SUM OF THE PARTSA digital-only card's value is largely determined by the amount and variety of outboard equipment that can be connected to it. By itself, the Dakota matches the competition based on its digital audio features alone. What puts the Dakota ahead of most of its rivals is its stand-alone MIDI capability. Moreover, very few competitors offer ADAT synchronization features beyond the ability to sync the sample rate of the card to a Lightpipe input.

The Dakota really comes into its own, however, when used with Frontier's other products. As I mentioned earlier, the Montana daughtercard adds 16 more ADAT channels, as well as video/word-clock input synchronization and ADAT sync output, so the computer can be placed in any slave position in an ADAT chain. The Sierra MIDI interface expands the Dakota's MIDI capabilities even further and provides SMPTE in and out. And the Tango24 converter gives you eight channels of A/D/A, along with word-clock in and out, at a very reasonable price. What's more, it sounds great.

The only real drawback to using a customizable system like this is that it initially costs more than a prepackaged audio card/multichannel box. Even so, the price of the Dakota/Tango24 bundle competes well with those of prepackaged setups. And when you consider that the Dakota/Tango24 combo offers more flexibility and expandability, the price difference pales in comparison to the difference in value. Besides, the Montana and Sierra hardware options are relatively inexpensive, and you can buy them as your needs and budget dictate.

The only specific black marks that I can give to the Dakota are its current lack of DirectX drivers (although Frontier hopes to have one by the time you read this) and its inability to sample at 96 kHz. However, most other multichannel cards don't sample at that rate, either. Besides, given the current level of technology, I don't want to sacrifice audio tracks or overburden my computer just to move up to a standard that is often used mainly for marketing hype.

Beyond these gripes, I have nothing bad to say about the Dakota, Montana, and Tango24 devices. In fact, I am so impressed with this system that it is the next planned purchase for my studio.

Zack Price is a digital audio editor and Windows digital audio consultant in the Chicago area.

HIGH SIERRAAlthough the Dakota card has a 2 x 2 MIDI interface that many would probably find adequate for their needs, some users require more than the 32 stock MIDI channels. For them, Frontier Design Group offers the Sierra ($299), an 8 x 8 (128-channel) 1U rack-mount MIDI interface/patch bay. The Sierra connects to the Dakota by means of a 15-foot, 8-pin cable. The cable length proved to be more than satisfactory when it came time for me to connect my MIDI rack to the Sierra and my computer.

The first seven MIDI In and Out ports are located on the rear of the unit, and the eighth ports are located on the front panel. This design makes it easy to plug in a MIDI master keyboard or to switch among different types of MIDI controllers as the situation dictates. For example, I use a MIDI keyboard controller to play in lead parts, a percussion controller for rhythm parts, and a MIDI fader unit to input various types of MIDI controller data. I never use all three devices at the same time, so I find it helpful to plug and unplug these pieces of the Sierra's front panel as needed.

A pair of 11/44-inch jacks is provided on the rear panel for sending and receiving SMPTE time code. The SMPTE output level can be adjusted in the Dakota's software control panel to +4 dBu or -10 dBV. You can monitor SMPTE time-code status with the SMPTE indicator lights on the Sierra's front panel. The bottom indicator shines green when SMPTE output is active. The red light glows when the Sierra is locked to incoming SMPTE time code, and it doesn't light when SMPTE input is inactive. The indicator blinks slowly when the SMPTE input is receiving a valid stream of SMPTE frames but the Sierra is not locking to it; the light blinks quickly when SMPTE input is active but not receiving a valid stream of SMPTE frames. The Sierra also has two sets of eight status indicators that show the presence of MIDI input and output activity.

A word of warning to Windows 95 users who wish to use the Sierra: Windows 95 limits the number of MIDI devices that you can install. This includes physical devices, such as stand-alone MIDI interfaces and those that are part of sound cards, as well as virtual MIDI interfaces including those used with sound-card and software synthesizers. If you exceed this device limit, your system will treat you to a nasty crash. Because adding in the Sierra's eight ports leaves you with no more than two or three other usable MIDI devices in your system, you may want to disable or remove any that you don't plan to use. (Windows 98 users don't have to worry about this problem because the limitation has been corrected in the newer operating system.)

MONTANA WILDHACKTo those who never seem to have enough, Frontier Design Group offers the Montana daughtercard ($249), which adds 16 more channels of digital audio to the Dakota card. The Montana has two pairs of optical I/O, and as with the Dakota, each can be used for 8-channel Lightpipe or 2-channel S/PDIF digital audio. In addition, the Montana has a 9-pin connector for ADAT sync output. When both the Montana and the Dakota are installed, the computer can function as a slave device anywhere within an ADAT chain. This allows the computer to follow incoming ADAT time code without affecting the operation of other ADAT devices down the chain.

The Montana also includes an RCA connector that can be used for video sync or word-clock input. Although any audio RCA cable can connect to the video/word-clock input, you should use a 75-ohm coaxial video cable. Alternatively, you can use a BNC cable with the Montana's supplied BNC/RCA adapter. The Montana also comes with an internal video connector that can attach to digital video cards like Pinnacle Systems' miroVideo DC-30. Keep in mind, though, that you can't use the internal and external video connectors at the same time.

Because of its unique design, the Montana can be installed in either a PCI or ISA slot adjacent to the Dakota card. The Montana comes from the factory ready to be put into a PCI slot; however, if you turn the card upside-down and exchange its faceplate with the supplied alternate, you can install it into an ISA slot. In both instances, the Montana fits into the 40-pin connector on the Dakota card. (The connecting cable is extremely short, which is why you have to install the Montana in a card slot adjacent to the Dakota.) Once the Montana is installed, the Dakota's drivers and its software control panel are able to automatically recognize it. Furthermore, no additional IRQs are required.

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