The SoundForce uVCF 6 is an upcoming 6HP Eurorack module that provides a voltage-controlled low pass filter selection between 4 poles (24db/octave) or 2 poles (12db/octave), with FM CV input, VOCT input, and Q CV input. The filter is a Eurorack interpretation of the Juno 60/106 VCF section, built using modern and widely available parts, as the original custom ICs are now obsolete and unavailable. The module also features loudness drop compensation (LDC) to avoid signal loss with high levels of resonance.
The SoundForce uVCF 6 boasts the same topology of VCF as that of the Juno 60/106, despite sounding differently due to various factors like the different base clock frequency of the DCOs, the different SAW directions, and different packagings of the ICs. The original IR3109 custom IC, including 4 OTAs, was used in the Juno 60's VCF, while the 80017A IC/PCB module incorporating both the IR3109 as well as the BA662 was used in the Juno 106. As the original custom ICs are no longer available for purchase, the SoundForce uVCF 6 uses the popular Texas Instruments LM13700 dual OTA IC to recreate the VCF using modern and widely available parts.
The uVCF 6 is a voltage-controlled low pass filter with a selection between 4 poles (24db/octave) or 2 poles (12db/octave). The travel of the FREQ pot has been calibrated to provide the best experience in the original 4 poles mode. The FM CV input modulates the cutoff frequency of the filter and has an attenuverter. The VOCT input closes the filter more or less based on the pitch of the note played by your musical CV source and can be used to "play" the filter when it is self-resonating. The filter will be in tune across about 8 octaves, and self-resonance occurs when the RES pot is around 4 o'clock or higher. The resonance can be also voltage-controlled using the Q CV input, which has an attenuator.
Loudness drop compensation (LDC) is a unique feature of the SoundForce uVCF 6 that addresses the usual input signal loudness drop with high levels of resonance. However, users need to lower the input signal and/or VCA level to avoid distortion since LDC requires some extra headroom.
In conclusion, the SoundForce uVCF 6 is an impressive Eurorack module that brings the character of the Juno 60/106 VCF section into the modern Eurorack format. Its voltage-controlled low pass filter selection, FM CV input, VOCT input, Q CV input, self-resonating capability, and loudness drop compensation enable outstanding filtering and sound creativity. Anyone who loves the sound of the Juno 60/106 and wants to incorporate its VCF section into their Eurorack setup should check out the SoundForce uVCF 6 once it becomes available in November 2021.
Example Usage
If you're new to using filters in your Eurorack setup, the SoundForce uVCF 6 is a great place to start. Connect your audio source to the input jack and adjust the Frequency and Resonance knobs to shape your sound. Want to get more creative? Use the FM and QCV inputs to modulate the filter cutoff frequency and resonance, respectively. And if you're encountering a loudness drop with high resonance, just engage the LDC switch to compensate for the drop. The uVCF 6 is an easy-to-use and versatile filter that will bring a new level of depth and dimension to your music.
An intermediate-level usage example for the SoundForce uVCF 6 module is using the filter's FM CV input to modulate the cutoff frequency of the filter. By connecting an LFO or sequencer to the FM CV input and adjusting the attenuverter, the cutoff frequency of the filter will be modulated in sync with the modulation source. Experimenting with different waveforms and modulation rates can lead to interesting rhythmic variations in the filtered audio signal. Additionally, using the Q CV input to voltage-control the resonance of the filter can add even more character and expressiveness to the sound.
Further Thoughts
One way to use the SoundForce uVCF 6 would be to use it as a creative tool to shape sounds in real-time during a live performance. For example, the uVCF 6's 4 pole (24db/octave) low pass filter could be slowly opened during a build-up to create a sense of tension and anticipation, before being dramatically closed to cut out high frequencies and create a drop. The resonance control could be used to self-oscillate the filter, creating an explosive burst of sound that could be choreographed with visual effects and lighting for a powerful, multi-sensory experience. The uVCF 6's compact size and voltage-controlled inputs also make it easy to integrate with other eurorack modules, allowing for endless possibilities when it comes to sound design and performance.