pro-audio products

dual channel optical compressor

Taking over where our classic SOC-1.1 left off, we announce the new Velox dual channel optical recording compressor.

dual optical compressort stereo optical compressor

front view grey version front view black version rear view

design features


We first manufactured the SOC-1.1 in 1999 and it brought to the market an optical (light dependant resistor) compressor with more user control than what was available at the time (LA series for example). The unit was emmensly popular and we built hundreds of them, but the construction was a bit messy and time consuming to build, so we recently retired the SOC-1.1 and have replaced it with the Velox!

new features

So the Velox sports the same amazing compression character of the original SOC-1.1 but we have added a MIX control so you can blend the input signal with the compressor output, and we have installed a BASS filter into the side chain to reduce the sensitivity of the compressor at low frequencies. We have also introduced more options to cater for your budget. The entry level Velox is available with high quality Texas Instrument audio opamps or you can opt for the high end Class A discrete transistor BE41 amplifiers. In addition we offer an optional Lundahl LL1517 transformer output that can be fitted to both versions.

control genius

The Velox is very easy to use for recording individual tracks or on the stereo mix buss because of the "soft knee" characteristic. The AUTO attack and release settings have been perfected to provide natural compression and in many cases that's all you will ever need for acoustic or vocal work. The MIX control allows you to use the 20:1 (virtually brick wall limiting) compression and blend that with the input for more "heavy" sounds - the options are virtually endless - but what ever you choose works!.

The same compressor characteristic as the original SOC-1.1 but with additional features.
Optional fully discrete transistor Class A or integrated circuit signal path.
Smooth soft knee compression - does not dig holes in your tracks.
Mix control for blending the uncompressed and compressed signal further enhances the ratio selections.
Side chain high pass filter (bass mode) for more bass punch on full mixes.
Boutique hand made with loving care in New Zealand.
All high quality components and controls to last a life time.

Related products - | SOC-20 mid/side compressor | SOC-M mastering opto compressor | Essence 500 series optical compressor |


To cater for your price range, we offer the Velox in two versions. The IC version uses nice Texas Instrument high end integrated circuit opamps in the signal path or you can opt for the DC version which utilises our Buzz Audio BE41 discrete opamps. Both versions can be supplied with a silver or black face plate. In addition, a Lundahl LL1517 output transformer can be fitted and this feeds the second set of output XLR's on the rear panel.


Velox-IC | US$1970 | €1720 | £1495 |
Velox-DC | US$2320 | €2035 | £1750 |
Velox LL1517 Output | US$220 | €200 | £174 |

controls and functions

DRIVE - turning it clock wise increases compression, which is way more sensible than counter clock wise!
MAKEUP - variable control that adds up to 15dB gain after the compressor section to correct for lost level.
MIX - variable control that allows you to mix between the input signal and the compressor output (post the makeup control).
COMP IN - Push button switch to bypass or engage the compressor, (hard wire bypass).
BASS - Push button switch that engages a high pass filter into the side chain to reduce the sensitivity of the compressor at low frequencies.
METER G.R./O.P. - Push button switch to select the display on the VU meter of the amount of gain reduction or the output level.
ATTACK - rotary switch with FAST (1mS) 25mS, 50mS selections plus our excellent AUTO mode.
RELEASE - rotary switch selects recovery time of 100mS, 200mS, 400mS, 800mS, 1600mS and a superb AUTO mode.
RATIO - rotary switch with 4 settings for depth of compression, 2:1, 5:1, 10:1, 20:1.
There is also a handy power ON/OFF switch and a channel A/B LINK switch which soft links the sidechain circuit, useful when used on stereo mixes.


Maximum Input Level Line; +32dBu
Maximum Output Level Line; +27dBu
Noise (measured with no make up gain); -95dB A weighted
Gain; variable 0dB to +15dB
Operating Level; +4dBu = 0VU on meter
Frequency Response (measured with no gain reduction);
Direct Output 5Hz to 240kHz
Transformer Output (if fitted) 5Hz to 320kHz
Harmonic Distortion (no gain reduction);
Direct Output 0.0062% @ 100Hz, 0.0062% @ 1kHz, 0.009% @ 10kHz, 0.0098% @ 100kHz
Transformer Output 100Hz-0.2%, 1kHz-0.05%, 10kHz-0.01%, 100kHz-0.01%
Harmonic Distortion (with 20dB gain reduction Attack AUTO, Release AUTO, 10dB make up gain, 5:1 ratio);
100Hz-1.5%, 1kHz-0.05%, 10kHz-0,02%, 100kHz-0.01%
Mains Voltage; 110-115Vac or 220-240Vac switchable.
Weight; 4.1 kg net, 6.8kg shipping.

  Buzz Audio Ltd
  New Zealand
  Ph +64(0)3-577-5597

  send us an email

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