Buzz Audio SOC-MA

Description

A precision stereo optical compressor optimized for analogue mastering featuring a mid side matrix and a balanced side chain insert point.

Mastering focus

Due to popular demand we have released a mastering version of the SOC-20 optical compressor. The SOC-MA mastering version replaces the DRIVE and GAIN pots of the SOC-20 with stepped Elma attenuators for repeatability. We have also adjusted the RATIO’s to suit mastering tasks and all the ratio’s feature our famous “soft knee” characteristic. The SOC-MA signal path utilizes our Class A discrete BE41 transistor amplifiers powered by a special low impedance power supply for vibrant sonic detail. As standard, the SOC-M is fitted with a Lundahl LL1517 while the SOC-MA is fitted with a transformerless direct drive output stage.

Analog mid-side processing

But not only is the Buzz Audio SOC-MA a stereo compressor, it also incorporates a Mid-Side (or sum and difference) encoder and decoder which is a very powerful mastering tool. When set to MS mode, signals that are common to left and right are processed by Channel A and the left to right difference signals by Channel B. In addition, when set to MS mode, the mid and side signals are available as balanced outputs on the rear panel insert send XLR’s

Side chain design

At the flick of a switch, a 12dB/octave high pass filter at 170Hz reduces the compressor sensitivity to low frequencies for more bass punch. We have also included a fully balanced side chain insert point so you can add additional equalisation to the compressor characteristic. The side chain monitor function allows you to hear what is returning into the insert point (the side chain) and you can also monitor the mid or side signals when the compressor is used in MS mode.

Dynamic range control

The 5 ratio settings feature a soft knee characteristic whereby the selected ratio is only actually acheived at 10dB of gain reduction. Therefore very gentle compression is available when using 2:1 and 3:1 and even 10:1 is usable for material that needs stronger dynamic control. The unique differential side chain circuit of the SOC-M splits the audio into positive and negative waveform and processes it separately (attack and release parameters) with the resulting balanced signal controlling the Buzz Audio BE45 electro-optical attenuator. There are 5 compressor attack settings and 6 release settings that cover a wide range of response possibilities. In addition, our clever auto modes produce very musical results. The auto attack adapts to incoming audio rise time, and the auto release will decay quickly from short impulses but longer from sustained or low frequency signals.

Specifications:

• Maximum Line Input Level; +32dBu
• Maximum Line Output Level; +27dBu
• Maximum Input/Output Level Side Chain Insert; +22dBu
• Noise; -95dBu Stereo Mode, -90dBu M/S Mode (measured with no make up gain and A Weighted).
• Gain; variable from 0dB to +15dB
• Standard Operating Level; +4dBu = 0 VU meter display.
• Size 2 Unit 19″ rack mount, (482Wx88Hx300D).
• Power requirements; 230V/115V selectable, IEC detachable power cable.
• Shipping weight; 8kgs
• Specifications are typical of a production unit and are subject to change without notice. 0dBu reference = 0.775 volts RMS.

Additional information