Frap Tools Cunsa Quad Filter

CUNSA is a quadruple analog pingable multimode resonant filter, saturator, mixer, and oscillator.

It is our sound seasoning tool: it can gently even a patch, applying a final touch, or it can set it on fire with a ridiculous amount of spice. It’s up to you and your cooking style!

It consists of four multimode resonant filters with a custom saturation and feedback control that you can use independently or in various combinations and roles thanks to a series of seminormalizations.

Four Analog Resonant Multimode Filters

CUNSA features four state-variable filters that can be used independently or linked and mixed. Each filter provides three behaviors simultaneously: lowpass, bandpass, and highpass. Each behavior has a 12 dB/oct slope, except for the lowpass, which can be either 12 or 24 dB/oct.

Unique ‘Character’ Circuit for Feedback and Distortion

CUNSA handles feedback and gain staging with extreme control and versatility. Besides the usual Q control that emphasizes the cutoff frequency, the Character circuit defines the amount of soft clipping when the filter overloads. High clipping guarantees a controlled behavior with fat tone and pure resonance, while low or no clipping lets the signal saturate the filter stages and make it scream.

V/oct Tracking and Quadruple Oscillator

Each filter responds to the V/oct signal with excellent tracking. It is thus possible to move the cutoff frequency along with the main melody or make CUNSA resonate with no input and transform it into a multiple oscillator. The V/oct inputs are seminormalled so you can control more filters with the same CV. Easy chords stabs!

Ping and Ring

CUNSA is ideal for percussive and organic tones. The Ping circuit offers a behavior similar to the BRENSO but AC-coupled. Instead of shooting the frequency to the moon with any trig, CUNSA gently responds to different incoming gates with a selectable decay curve. The Ping circuit can thus create natural decay sounds when fed with trigs or smoother envelopes with any other voltage, like a linear integrator with a custom decay.

Besides this, you can also feed the filter’s audio input with trigs and make it ring at high Q settings.

Linked or Individual Filtering

The four filters can work independently or arranged in groups through seminormalled inputs and sum outputs. CUNSA can thus be a 4×1, 2×2, or a massive 1×4 filter. Even odd configurations are possible, like 1+2+1 or 3+1. Mono, stereo, or quadraphonic audio is at your fingertips.

Filter and Combo Behavior

When the filter behavior is set to COMBINED, every control of the cutoff frequency also affects the input VCA, reducing the signal amplitude and saturation as it approaches the lowest range. It can make organic decays with the ping circuit or tame the low range at high Q and Character settings.

Filter and Combo Behavior

When the filter behavior is set to COMBINED, every control of the cutoff frequency also affects the input VCA, reducing the signal amplitude and saturation as it approaches the lowest range. It can make organic decays with the ping circuit or tame the low range at high Q and Character settings.

Analog Mixing Stage and Group Outputs

Every filter output can be routed to an analog mix bus that sums the four filters and outputs them in three combinations: all, 1+2, and 3+4. These outputs allow for versatile audio processing. Just like we did with FUMANA, we added a gentle shelving EQ for the higher frequencies of the All output to provide additional timbral variety.

CV Inputs with Attenuators

Besides the seminormalled inputs, every filter features additional CV inputs for cutoff frequency, Q, and Character, each with a dedicated attenuverter.