SoundForce VCF/VCA 6 Module (18HP)

Full Description

60/106-style design

The VCF/VCA 6 module takes inrpirations from the voltage-controlled filter (VCF), the voltage controlled amplifier (VCA) and the high pass filter (HPF) sections of two renowned vintage synthesizers of the 1980s; to create a filter in the form of a Eurorack 18HP module.

This is the SoundForce VCF/VCA 6, an innovative and nostalgic concept that brings the effects of the HPF/VCF/VCA segments of two extremely popular synthesizers to your modular setup. The SoundForce VCF/VCA 6 is an all-in-one rendition of classic 60/106 style synthesizer filters. SoundForce has replicated the original filter by studying the original manuals and documentation. Integrated into the module are the Texas Instruments LM13700 OTA IC chips which achieve accurate emulation of the venerable 80s filters.

The VCF section

The voltage-controlled filter section is a low pass filter with the option to switch between 2 pole (12db/octave) and 4 pole (24db/octave) allowing you to choose your desired cut-off frequency. The frequency slider (FREQ) is calibrated for the 4 pole option to give you the best experience with the wider frequency range. Shape your sound with the resonance slider. When the resonance slider (RES) is set to position 9 and above self-resonance occurs producing a sine wave which means you can effectively play the filter by adjusting the frequency and inputting a sequencer or CV equipped keyboard; with the filter being in tune across 8 octaves.

The VCF has two frequency modulation inputs (FM1 and FM2) with the FM1 equipped with a negative and positive polarity inverter switch. The negative polarity allows the FM1 fader to be used to dampen sounds rather than increase them with the positive. The Q CV input can be used to modulate the resonance to your preference.

The Mixer/VCA/HPF section

The SoundForce VCF/VCA 6 has a two input mixer. This means you can send two different sounds into the filter to blend them together. Combine your primary oscillator and a sub-octave generator together in one module, without the need for a separate mixer. The voltage-controlled amplifier is a single OTA VCA. This allows the gain to be set by an external signal through the CV input. The VCA and the CV input both have faders for manual adjustment.

A High pass filter (HPF) is also featured on the VCF/VCA 6. The high pass filter is inspired by the 60/106 HPF which removes low frequencies excellently. The HPF is stepped in four stages like the authentic 60/106 models; from step one to four, you can filter out the low frequencies. Step zero acts as a bass boost which is also a feature of the original 106. This bass boost is in addition to the LDC.

Loudness drop compensation (LDC)

SoundForce has equipped the VCF/VCA 6 with a loudness drop compensation (LDC). This feature compensates for a reduction of low frequencies that occurs when the resonance is increased. The LDC drives the low frequencies of your filtered sounds. For this to work, you will need to lower the input signal and/or VCA level to avoid any distortion, as the LDC process requires extra headroom.

Features

• Based on the filter section of an iconic vintage synthesizer
• 2 channel mixer allows you to filter 2 different sounds at once
• 2 frequency modulation inputs with FM1 having a negative polarity switch
• 60/160-style voltage-controlled low pass filter
• Classic single OTA voltage controlled amplifier
• High pass filter with integrated bass boost
• Choose between 4 pole (24dB/octave) and 2 pole (12dB/octave) frequency range
• Ideal for sound shaping and sound design
• Meticulously recreated circuitry with improved and refined components
• LDC (Loudness Drop Compensation) can be activated via onboard switch
• Can self-resonate when RES pot is at a certain position (around 4 o clock or higher)
• VOCT input can be used to close the filter (dependant on your CV source)

Specifications

• Module Size: 18HP
• Depth: 38mm (including power connector)
• Power: +12V 91mA, -12V 51mA
• V/OCT, FM1, FM2 (input range) : -5 to 5V
• QCV, ACV (input range) : 0V to 10V
• Product Code: SFC-VCF/VCA6