Buzz Audio SOC 1.1 Optical Compressor

In my opinion it’s really simple to describe what a good compressor sounds like. A good compressor sounds just like what you put into it, only bigger. Compressors that are not so good, make things sound smaller, or rougher, distorted, or brittle, dull, or uninteresting. Feel free to pick one or more. Of course, sometimes that’s just what you want to provide an interesting effect. Most of the compressor/limiters that one would see in a top range studio, however, are going to be of the first variety. Buzz Audio is a small company in New Zealand that manufactures two main products, a stereo microphone preamp, and the SOC 1.1 stereo optical compressor. I am going to let the cat out of the bag when I tell you that the SOC 1.1 is one of the very best bargains in pro audio right now.

The product
The SOC 1.1 is a two-rackspace unit constructed of steel and aluminum, finished in black with blue legending of the controls. It is configured as a dual mono unit, with a channel-linking switch which may be engaged if stereo operation is desired. In the tradition of the venerable Universal Audio compressors, the SOC 1.1 is an optical compressor. For the uninitiated, this means that instead of using a voltage-controlled amplifier for gain reduction duties, an optical device is used. The optical device in some compressors consists of a light bulb shining on a photo resistor; one newer design used an LCD panel as its element.

The SOC 1.1 uses a proprietary gain reduction element, which is comprised of four selected miniature Light Dependant Resistors illuminated by a four element LED light block. By utilizing four LDR’s the varying tolerances of the LDR devices can be evened out, netting more predictable results. The LED light block is driven differentially, similar to an output stage in a power amplifier, where one half of the block handles the positive waveform and the other the negative waveform. Other construction details include the utilization of high quality internal componentry throughout the unit, including Bourns conductive plastic potentiometers, C&K micro switches, and high-slew rate opamps.

Front panel controls include the following; power (which interestingly functions as on when the switch toggle points down – perhaps this is a result of Buzz audio being located upside down in NZ?), a stereo link switch that ties the sidechains of the two channels together. As a precautionary note, the individual channel controls must be set identically for the stereo link function to operate correctly. The remaining front panel controls are doubled (one for each of the SOC 1.1’s two channels) Drive, Output, Ratio (2/5/10/20), Release (1/2/4/8/16/auto), Toggle micro switches for Attack (fast/slow/auto), Meter Functionality (input/gain-reduction/output), and a hard relay Bypass (which like the power switch, down equals on).

In addition, there are two very large VU meters which are backlit internally by an ingenious method. A small circuit board with large yellow LED’s (in an arc which matches the scale of the meter) is fitted directly behind the meter itself. No bulbs to change…ever! Inputs and outputs are balanced on XLR connectors (pin 2 is hot, by the way), and the unit is fitted with the standard IEC detachable power cord. The SOC 1.1 may be user configured for 120V or 240V operation. Fuses for both voltages are included with the unit. All of the controls work smoothly and as expected, and the build quality is excellent. Looking under the top cover makes it apparent that Buzz Audio is serious about making a high quality product. My only quibble is that the blue legending on the front panel is hard to read.

In Use
For the past few months I have been using the SOC 1.1 almost exclusively when tracking critical vocals and instruments. I have found the SOC 1.1 to add a pleasing quality to almost every source fed through it.

One of my favorite applications for the SOC 1.1 has been on lead vocals, using a Microtech Gefell M71K microphone, the excellent DAV Electronics Broadhurst Gardens No.1 microphone preamp, and the Buzz compressor direct to my 2” analog machine. Excellent VU metering on the front panel (switchable between input, gain reduction, and output levels) made it really easy to set the amount of gain reduction whilst controlling the overall amount of level sent to tape, all without having to move away from the unit. Depending upon the setting of the controls, vocals could be processed mildly for an apparent increase in size, or radically for an apparent increase in intensity!

Guitars took on a nice sense of fullness through the Buzz, moving forward through the mix to become much more involving and animated. On a recent session I used the bargain basement Audio-Technica 3035 microphone on a Jean Larivee jumbo acoustic guitar into a Peavey VMP tube mic preamplifier feeding the Buzz. Recorded from three feet away, the overall sound was THE classic 70’s Jeff Lynne guitar sound. Present yet spongy in a good way. Flipping the bypass switch on the SOC 1.1 quickly highlighted how much of this sound was due to the compression!

“I need more triangle!” Anyone who has seen that Blue Oyster Cult video will know what I mean, but the Buzz compressor allowed me to very easily set the level of click and ring on a recent triangle track. I was able to dial in a very nice sustain and keep levels in check. I had a similar experience with tambourine.

Direct bass tracks sounded really nice through the Buzz. Working with NY session bassist Robert Graham (a very dynamic five string player) I utilized both channels of the SOC 1.1, one run into the other. This yielded a very smooth track, which had no nasty compression artifacts, just big, warm, and round bass.

The only application where the Buzz did not shine was on a badly recorded snare track. This particular track had a ton of leakage on it, and compressing it didn’t improve matters at all. I am usually not a big fan of gating snare drums, finding that gating most often imparts artifacts worse than the benefits of the gating. Most of the time the right compression will do the trick. Not this time! On a brighter note I found the SOC 1.1 to work much better with a more cleanly recorded snare, very much offering a nice user variable balance between stick, snare, and sustain depending upon settings.

The SOC 1.1 compressor is fully competitive with units both modern and vintage, the sound, build quality, and overall vibe is world class.  If you are in need of a high quality stereo compressor, and are not interested in VCA or tube based units, I think that at this point in time, one can do no better than the SOC 1.1. Highly recommended.

Superb sound
Superb value
Excellent build quality

Control legending hard to read in low light

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