Rockruepel Sidechain One Mono VCA Compressor with Sidechain Filtering

sidechain.one is one of the only compressors build around a full bandwidth filter in the sidechain with the ability to precisely select which frequencies trigger the compressor. This manual will help you learn about sidechain.one, but as with all high-quality analog equipment, the more you use it, the more applications you will discover. We encourage you to be curious, daring and experimental as you explore sidechain.one. And we invite you to share your discoveries with us. Welcome to rockruepel!

sidechain.one takes a new approach to what a compressor can and should do. Sidechain.one isn’t colored and doesn’t impart its own character on your sound sources – it precisely affects only what you need it to and leaves the rest of the frequency spectrum alone.

Using sidechain frequencies has become a standard technique in mixing and mastering. Most of the time, it is used in the digital domain with plug-ins that can offer this flexibilty and versatility thanks to the nature of digital audio. One of the trendsetters for this approach is Luca Pretolesi.

His signature sound is characterized in part by his use of sidechain frequencies in the compressor for a variety of styles, in mono, stereo and specially in M/S applications. Inspired by his workflow, we created a compressor that brings the discreet and pure processing of a digital plug-in into the analog realm. This is sidechain.one.

FREQUENCY FADER
The frequency in the sidechain is defined by two faders. Both faders span the entire audible bandwidth from 20Hz to 20KHz. Using these faders, you can dial in the frequency range that is sent to the detector of the compressor.

We suggest using the top fader to set the highest frequency the detector will receive and the bottom fader to set the lowest frequency the detector will receive. Everything between these two frequencies is the trigger for the compressor to act on. The arrows show you your start points and which direction to move the faders in.

BAND SELECTOR
The band selector restricts which frequencies trigger sidechain.one. Each fader is connected to a selector switch that lets you choose which range of frequencies the fader can adjust between High, Mid and Low. These are color coded as High = Green, Mid = Yellow and Low = Red. Approximately values can be seen here.

IN
Individual hard bypass switches sidechain.one on or off.

LISTEN
Preview what is being sent to the sidechain equalizer path. You can also use this feature without compression to use sidechain.one as a high-quality high pass or low pass filter.

LINK
Two sidechain.one units can be linked. When you link the channels, the unit will compress both channels identically based on whichever unit’s threshold is triggered at any given moment. For this reason, it is typically a good idea to set the units identically when operating in LINK mode.

However, there may be instances when allowing one unit to dominate the other is desired (for example, when doing Mid-Side processing). The equalizers are not linked and should be set the same.

ACTIVE RATIO
Determines the ratio of the compressor, here are some examples.

• 1:10 — HARD— typically this setting provides most audible compression
• 1:4 — MEDIUM — good to start here
• 1:2 — SOFT— very smooth operation

THRESHOLD
Can be set from +15dB to – 44dB

ATTACK
Can be set from 0.1 ms to 120ms

RELEASE
Can be set from 0.1 to 1.2s

OUTPUT GAIN
Can be set from 0dB to 10dB

INPUT XLR
XLR Balanced Connection

OUTPUT XLR
XLR Balanced Connection

LINK
TS Connection

DC INPUT
External Power supply for use from 110V – 240V. A standard IEC power cord is used.

Frequency Response
• 40Hz – 15 kHz ± 0,09 dB
• 20Hz – 20 kHz ± 0,22 dB
• Amplification 0 to +10 dB
• Max Output level ( 40Hz k3 -50dB ) +22dBu
• Voltage Unit +/- 15V DC
• Powersupply 100-240V AC

• Power usage 3,5W
• Dimensions B/H/T 483 mm (19“) 44,2 mm (1HE) 135mm
• Weight 1,15 kg

Input symmetric
• Input resistance ⪴ 22kOhm
• Input damping at 15KHz ⪴ -45dB

Output symmetric
• Output resistance ⪴ 80Ohm
• Output damping at 15KHz ⪴ -42dB
• Harmonics k3: at +4dBu

Noise floor
( at + 4dBu Output at +10dB )
• pGer ⪴ -79 dBqs ( CCIR 486 )
• pFr ⪴ -84 dBq ( Bandwidth 10Hz – 30 kHz)

Rockruepel Sidechain.One Manual