Rockruepel Sidechain.one

VCA compressor with sidechain filters

The Rockruepel Sidechain.one is a single-channel VCA compressor with controls for threshold (+15 dB to -44 dB), attack, release and output gain. A switch gives you access to three ratio settings (1:2, 1:4 and 1:10). With wide attack and release ranges, the compressor is designed to suit a broad spectrum of applications. The attack can be adjusted from 0.1 to 120 milliseconds, while the release can be set to anything from 0.1 milliseconds to 1.2 seconds.

According to Rockruepel, the components of the compressor were carefully selected to provide exceptional fidelity and a transparent and neutral sound. The inputs and outputs are on XLR jacks. For stereo applications, two units can be linked via the link jacks at the back and the link switches. This allows you to use the Sidechain.one on stereo busses or full mixes during mastering. If you buy the stereo bundle, the link cable is included.

So where does the Sidechain.one get its name? The compressor offers a pair of high pass and low pass filters, which allow you to shape the sidechain signal, thus affecting how the compressor responds to the input signal. The filters are controlled by sliders, which provides a good visual representation of their settings. You can choose from three frequency ranges for the filters: 20–200 Hz, 150 Hz – 2.3 kHz, 1.5–20 kHz.

The Listen switch lets you preview the sidechain signal for adjusting the filters precisely. With these features, the Sidechain.one lends itself to a wide range of precision compression tasks. The Listen feature even lets you use it as a high-quality band pass filter if you wish, although that’s probably a bit of a waste.