Rossum Electro-Music / Linnaeus Silver

A 2-channel filter that is an evolution of the multi-mode filters (HP/BP/LP/N) typified by the OBERHEIM SEM, with a wide range of parameters that dramatically change the sound.

Linnaeus is Rossum's third filter module, following Evolution (a low-pass filter based on the filter in the E-mu Sytem2100) and Morpheus (a 14-pole Z-Plain digital filter in the E-mu Morpheus synthesizer). It is an innovative stereo state variable filter that is a highly evolved version of the multimode filter in the Oberheim SEM.

Linnaeus features two newly designed through-zero state variable filters that allow linear modulation of the resonance frequency from zero to negative frequencies while maintaining stable operation at all times. With extensive CV control of almost all parameters, Linnaeus allows new ways to control the natural response curve of the filters, allowing for subtle or dramatic sound effects. With its ""one knob per parameter"" interface, Linnaeus is well suited to real-time interaction and stimulates creativity.

The cutoff/resonance frequency of the Linnaeus is exponentially CV controlled from infrasonic frequencies below 20Hz to ultrasonic frequencies above 20,000Hz. At the same time, the resonant gain (Q) is exponentially CV controlled from 0dB to over 60dB.

The characteristics of the two Linnaeus filters are continuously variable, independently, from low pass, band pass, high pass, notch, low shelving and high shelving characteristics. CV control of the response characteristics is selectable separately for each of the two channels.

Linear through-zero modulation is driven by the built-in modulation oscillator and/or an external linear FM modulation input.

The CV-controllable modulation oscillator can track the linear frequency of the filter or operate independently. The output waveform of the modulation oscillator is continuously variable from off, to sine, triangle, sawtooth and square. The output of the modulation oscillator is summed with the external linear FM input and applied to the modulation index VCA, which controls a linear through-zero modulation index from 0 to 8 times. Of course the modulation index is also CV controllable.

Linnaeus features:

Very wide frequency range, from sub-audio to ultrasonic, with exponential CV control via precise 1V/OCT and attenuable CV input.
Through-zero linear frequency modulation via the internal modulation oscillator and/or external linear FM input.
Variable linear modulation index, CV controllable via attenuable CV input.
Exponential CV-controllable resonance (Q) from 0dB to over 60dB using 6dB/V and attenuable CV input.
Continuously variable response characteristics independently selectable for each of the two channels using the Response Enable buttons. Characteristics include low pass (12db/oct and 6db/oct), band pass, high pass (12db/oct and 6db/oct), notch, low shelving and high shelving.
CV control of response characteristics via attenuable CV inputs. Separate Response CV Enable buttons allow each channel's response to be individually enabled or disabled by CV.
Integrated modulation oscillator with waveforms continuously variable from off to sine, triangle, sawtooth and square. Its frequency is exponentially CV-controlled using the attenuable CV inputs.
Track control allowing the modulation oscillator to precisely track the index frequency of the filter.

Stereo input and output. Linnaeus can process a stereo signal or two independent mono signals. The two channels share the filter cutoff/resonance frequency, but the filter response characteristics can be controlled separately for each channel.

Linnaeus is robustly built like other Rossum Electro-Music modules, with thick aluminum panels, sturdy aluminum knobs, and high-quality components.

Another feature of Linnaeus: Ping Mode

The above feature description describes Linnaeus as originally conceived and designed by Dave. However, later in the beta testing process, good friend and tester Chris Meyer from Rossum Electro-Music suggested the possibility of a ""Ping Mode"" that would include some very powerful sound generation capabilities, where Linnaeus could function as a self-contained (no input required) stereo oscillator or FM percussion voice.

At first, we were hesitant to try to add a new feature to the existing interface, but after Dave prototyped it, we decided it was so cool that we had to include it in Linnaeus. So Ping Mode is included as an alternate firmware accessed by long pressing or double clicking the Egg button.

Width 16HP
Depth 25mm
Current Consumption
+12V : 155mA
-12V : 36mA