AudioControl Matrix
www.audiocontrol.com
AudioControl offers pro-audio quality in a 12-volt package with its powerful six-channel Matrix line driver.
Matrix Specs

Price & Contact: $199; 425-775-8461; www.audiocontrol.com
All tests done @ 14 volts unless otherwise noted.
Input Impedance: 40 kohms
Output Impedance: 49 ohms
Max Output Voltage: 9.9 volts (RMS) @ 1% THD+N
Gain Adjustment: –12 dB, +24.5 dB
Maximum Voltage Gain: 24.5 dB
Signal-to-Noise below Max Output: –122 dB
Frequency Response (20 Hz to 20 kHz, 1 kHz Ref.): +0 dB, –.08 dB
CMRR (below Max Output): –56 dB
by Brian Smith
The Matrix is a six-channel line driver that features balanced inputs, output metering, selectable ground isolation, and a subsonic filter. The components that determine the frequency of the subsonic filter reside in an IC socket in the signal path of channels 5/6. Our test unit came with a 33 Hz 18 dB-per-octave filter, but AudioControl allows you to choose whatever cutoff frequency you desire. Additionally, internal jumpers are configured to allow channel 5/6’s inputs to drive any combination of outputs. Internal jumpers also configure the input’s ground isolation and mode of operation. The inputs can be run either balanced or single-ended, and ground isolation options include 200-ohm, total isolation, and total lack of isolation.

Performance
Both the manual and the box that the Matrix was delivered in make reference to the ever-changing (and often horrible) weather conditions in Washington State. I’m not sure that there is actual proof that inclement weather produces better audio components, but I’ll assure you that no one was singin’ in the rain during the design or construction of this unit. The Matrix’s circuit board layout is impeccably neat and the overall construction gives the impression that the unit could be dropped from the fifth floor without adverse effect.

The results of our measurements on the Matrix bear a striking resemblance to some of the pro audio pieces that we play with from time to time. The Matrix met or exceeded all of its published specs, but the important issues are the source impedance of 49 ohms and nearly 10 volts of clean output. That makes it Mr. Line Driver to you, and you’d best smile when you say it, son. AudioControl claims that this beast will drive up to seven amps per channel — that makes a total of 42 potential amps if I can still multiply. With a source impedance of 49 ohms and a typical amp input of 20K, we figure the number would be more like three dozen channels per output — but what’s the difference once you get past seven? On the other hand, if those SPL guys find out that they can drive 200+ amplifiers with this thing, they might just be crazy enough to try it.

AudioControl’s user interfaces are usually quite good. The fact that they provide four-segment metering and pots that you can actually turn with your fingers on something as straightforward as a line driver indicates that they gave some thought to the end user. Hmmm...what’s the possibility of an AudioControl head unit?

Manual
Perhaps the funniest read in audio. There are certainly more laughable examples in the world of hi-fi, but there’s a big difference between laughable and funny. AudioControl’s marketing approach is great, (yeah, I can’t believe I just said that either). It’s nice to see that somebody in the manufacturing side of audio has a real sense of humor.

A logistically delightful line driver from the loquacious denizens of the great Northwest Rainforest. (Sorry, I just couldn’t resist the urge.)