Ego Systems has upped the ante for makers of computer audio interfaces. The company's ever-widening product line now includes the WaMi Rack 192X, which

Ego Systems has upped the ante for makers of computer audio interfaces. The company's ever-widening product line now includes the WaMi Rack 192X, which brings 192 kHz audio to the table.

The WaMi Rack 192X has four channels of audio input and ten output channels. All its A/D/A converters are 24-bit, offering a wide dynamic range (123 dB for input and 106 dB for output). The unit offers 16 channels of MIDI I/O and has excellent driver support.

The 192X has three components: a PCI host adapter, a 1U rackmountable audio interface, and a cable to connect the two. The 16-foot cable is the longest I've seen in such a product, and the extra length was certainly appreciated in my studio (my rack isn't very close to my computer).


Audio flows into the 192X through four ¼-inch balanced line inputs on the back of the rack unit or through the onboard microphone preamps. The preamp inputs appear as XLR jacks on the front of the unit, complete with switches for 48V phantom power. These jacks are not of the locking variety, and my cables weren't particularly snug in them — a little duct tape may be in order for your critical recording jobs. Switches let you select mic or line sources. Unfortunately, only two sets of phantom-power and input-source switches exist (each switch controls a pair of audio inputs).

Also on the front of the rack unit are level controls for each input channel and a headphone jack with a dedicated level control. The back panel contains MIDI In and Out ports, the line inputs, the host-adapter connector, and eight analog outputs on balanced ¼-inch connectors. A stereo monitor signal appears on a pair of XLR outputs, which carry the same signal as the headphone output (more on this later).

All of the analog inputs and outputs operate at +4 dBu and are not switchable to -10 dBV. That is unfortunate because it prevented me from running my MIDI sound modules directly into the line inputs. The lack of -10 dBV outputs also diminishes the product's capabilities for surround sound — consumer-grade A/V receivers are still a popular solution for monitoring 5.1 mixes in the studio.

A set of coaxial S/PDIF connectors that appear on the host card rounds out the product's audio I/O. I'd have preferred them on the rack unit with the rest of the audio connections (the less I have to fumble around behind my computer, the better). On the input side, the S/PDIF connector takes the place of analog inputs 3 and 4 (switchable with software). The S/PDIF output appears as outputs number 9 and 10 in your software applications. An optical S/PDIF (Toslink) input is available with the MI/O DI/O add-on card, which is sold separately. This optional card also has an additional coaxial S/PDIF I/O along with an extra MIDI In and Out.

Installation on my Pentium 4 running Windows 2000 was painless. I installed the host adapter into a spare PCI slot, connected the rack unit, and switched on my computer. Windows found the new device, I pointed it to the installation CD, and I was up and running. I was a bit confused by the multiple requests to reboot the system, having failed to note the manual's recommendation to ignore all but the last request for a reboot.


After installation, you'll use the 192X's Console application to control its features. The Console, which appears in your Taskbar (see Fig. 1), is efficiently laid out and provides most of its functionality in its main window. For example, there you can choose between the analog and digital inputs for channels 3 and 4 and enable either consumer or professional formats for the S/PDIF I/O. You can also select which one of ten different sample rates to lock to, or you can choose to let your audio application select a rate automatically.

If you have more than one 192X in your system (you can install up to four), you'll use a menu option in the Console to enable or disable them. To sync them all together, you'll need to set one card to Internal and the others to CardSync. You can also slave the 192X's clock to an incoming digital audio stream.

The Console's faders are rather fancy. Each stereo pair is presented with its left and right channels. As your mouse floats over the stereo pair, either the left or right fader lights up, indicating your ability to move it. Put your mouse between the two channels, and you can move both faders at once. If you have a mouse wheel, you can also use it to move the faders; you can even adjust how much the fader should move with each step of the wheel.

The Console has two sets of input faders and five sets of output faders. Each has a stereo VU meter and a numerical decibel display that doubles as a mute button. The input faders don't affect the signal recorded by your audio application. Instead, they control only what feeds to the 192X's monitor mix (you enable input monitoring with a button above the channel 1/2 output faders). If you like, you can monitor your inputs in mono or stereo.

The monitor signal routes to the headphone jack and to the XLR outputs on the back of the rack unit. However, it's worth noting that this is not a true monitor mix — only the four input channels and output channels 1 and 2 can appear here (the remaining eight output channels appear only at the direct outputs). And unfortunately, you cannot send the monitor mix to the S/PDIF output.

I was a bit confused by the presence of four additional sets of faders, which are labeled MME and numbered to match the analog output channels. These faders lack VU meters and represent their position as a percentage rather than a decibel value. I spoke to my contact at Ego Systems about them, and he said he uses them to mute the Windows System sounds. The manual states that I should use them to adjust the output level of the MME driver, which is “sometimes lower than its actual output level.”

WaMi Rack 192X Specifications Analog Inputs(4) balanced ¼" TRS (+4 dBu); (4) balanced XLRAnalog Outputs(8) balanced ¼" TRS (+4 dBu); (2) balanced XLRSampling Rates16-192 kHzMaximum Resolution24-bitDigital I/O(1) S/PDIF on coaxial connectorsMIDI PortsIn, OutMic Preamp4 channel, 48V phantom powerDimensions19.00" (W) × 1.75" (H) × 5.25" (D)Weight5 lb.

I'm not exactly sure what to do with them, but I can report that they work. I routed a GSIF-based GigaStudio instrument to the same set of outputs that Sound Forge (an MME-based application) was using. I could hear both signals, which speaks well of the 192X's multiclient drivers. Adjusting the MME fader for the output changed only the Sound Forge signal, and the GigaStudio instrument was not affected.


The 192X has impressive driver support. In addition to the standard Windows MME drivers, there is a multichannel MME driver (a subset of WDM, which Ego Systems recommends for use with Cakewalk's Sonar), ASIO support, and support for GigaStudio's GSIF. Mac OS X drivers should be available by the time you read this.

GSIF worked well for me. GigaStudio had no trouble finding the drivers, and I could bring the 192X's latency setting down to 64 samples (using a menu in the Console) without any audible artifacts. With this latency, I could play GigaStudio instruments in real time with no noticeable delay. Cakewalk's DirectX Instruments worked just as well in Sonar.

By far the coolest thing about the 192X drivers is DirectWIRE, which lets you route audio signals between the various audio technologies that are supported by the product. For instance, you can send the output of your MME-based DVD-player software to the input of your ASIO-based sequencer or record GigaStudio with your audio editor by routing GSIF outputs to MME inputs.

You make these connections with the DirectWIRE panel in the Console (see Fig. 2). This panel presents all ten channels of the 192X in multiple columns of inputs and outputs. You make a connection by drawing a patchcord, so that connecting ASIO output channel 3 to MME input channel 7 is as simple as a click and a drag of the mouse.

I routed GigaStudio to Cakewalk's Sonar with DirectWIRE, lowered latency settings everywhere I could, and turned on Input Monitoring in Sonar. Out of my speakers came a GigaStudio instrument, playable in real time! When you consider the amount of number crunching taking place, this is nothing short of amazing. Granted, Sonar did switch off its audio engine after a minute or so, but I'm told this has been fixed in the latest version of the software. And just for fun, I managed to record a Sonar DirectX Instrument using Sound Forge.

The 192X's drivers are also well suited for 5.1 DVD playback. I selected the multichannel MME driver in the Windows Control Panel, then downloaded a trial version of Cyberlink's PowerDVD program and configured it for six-speaker output. I loaded a copy of Pearl Harbor into my DVD drive and had the sounds of Japanese “Zeros” in six separate outputs of the 192X. It's a good thing the PowerDVD demo had a time-out feature or I might have missed my deadline for submitting this review!


To check out the 192X's preamps, I made a number of recordings. For comparison, I made similar recordings with my trusty PreSonus MP20 (a 2000 EM Editor's Choice winner) connected to the line inputs of the 192X. I applied RMS normalization to each recording in an attempt to remove any bias that could be attributed to different recording levels.

The 192X held up well. The MP20 sounded better, but the difference was very subtle — I can only describe it by saying the MP20 had better “clarity” across the frequency spectrum. In recordings with a full gamut of frequencies (such as acoustic piano and guitar), I heard each of the frequency components slightly better in the MP20 than in the 192X. My methods weren't particularly scientific, however, and your mileage may vary. So be sure to listen for yourself before you buy.

I also made recordings at several sampling rates to see if recording at 192 kHz really made a difference. I had no trouble recording at 44.1, 48, or 96 kHz (both at 16 and 24 bits) with any of my audio applications. However, only two of my programs support 192 kHz audio: Syntrillium's Cool Edit Pro and Sonic Foundry's Sound Forge.

Cool Edit Pro wouldn't record from the 192X at this sampling rate; it told me that my device doesn't support it. Sound Forge recorded the audio just fine, but then it gave me a “sampling rate unsupported” message when I tried to play back the audio. I tried reducing the bit depth, and I tried a mono recording. Neither helped. I've made Ego Systems aware of these issues, so hopefully they'll be resolved by the time you read this. (The manufacturer claims that 192 kHz recording and playback works properly under Windows XP with the XP service pack installed.)


The 192X is an intriguing piece of equipment. It has a good set of preamps, excellent driver support, and plenty of capability for recording and mixdown (including 5.1 projects, provided you can use the +4 dBu outputs). The documentation is minimal but adequate, though the translation (presumably from Korean) is rather rough. The company posts drivers and manuals on its Web site, but my attempts to retrieve them were often unsuccessful (according to Ego, the main server is in Korea, and the company is working to set up a mirror site).

All things considered, though, the 192X is worth a look. If you're in the market for a new audio interface, go check this one out.

Allan Mettsis an Atlanta-based musician, software/systems designer, and consultant.

Minimum System Requirements

WaMi Rack 192X
Pentium II/350 or Athlon/400; 128 MB RAM; Windows 98SE/2000/ME/XP


Ego Systems
WaMi Rack 192X audio interface
MI/O DI/O expansion card $59.99


PROS: Excellent driver support allows connections across technologies. MME driver supports 5.1 surround sound. Good-sounding preamps. Long host-adapter cable.

CONS: No -10 dBV inputs or outputs. Cables can pull out of XLR jacks too easily. Monitor mixing is limited.


ESI America
tel. (408) 519-5774