Joranalogue Audio Design

Notes: Belgian analogue innovators Joranalogue serve up an ultra-versatile filter module. Multimode flexibility meets self-oscillation for added sonic versatility. A hell of a lot of filter for the money.

Supplier's notes:
Representing the cutting edge in modular analogue voltage controlled filter (VCF) design, Filter 8 offers more possibilities and higher fidelity in 12 HP than ever before.

Starting from the classic OTA-style 4-pole cascaded lowpass (LP) topology, Filter 8 features separate LP outputs, each with their own character. Additional filter responses are achieved by pole mixing: 1-pole highpass, a special band boost and notch response, phase shifter and 4-pole bandpass. All outputs are available simultaneously.

Key to Filter 8's performance is the innovative resonant feedback circuit. By increasing the resonance, all outputs will resonate at the filter frequency, without any low frequency response loss. At higher resonance levels, self-oscillation is achieved, turning the module into an excellent 8-phase sine wave voltage controlled oscillator (VCO) with temperature and switchable gain compensation, low distortion, constant amplitude and accurate frequency tracking over at least 5 octaves. At sub-audio frequencies, Filter 8 can function as an 8-output voltage controlled slew modifier or 8-phase low frequency oscillator (LFO).

Simultaneous exponential and linear frequency modulation is possible, for classic FM tones or chaotic modulation. A hold feature is also provided, 'freezing' the output voltages manually or under gate control. This is useful for halting modulations, or as a sync-like effect at audio frequencies. The dedicated 'ping' input allows you to easily create crisp percussive sounds with different timbres.

While rooted in the legacy of classic synthesisers, Filter 8 provides a new approach to musical signal generators and modifiers: instead of simply a VCF, VCO, slew modifier or VCLFO, a single analogue module can now be any of those, and anything in between.

Notes: Any signal can be expressed in terms of a few parameters: frequency, phase, amplitude and timbre. It is through modulation of these aspects that synthesists create electronic sound. With Generate 3, it is now possible to create a signal and control all its parameters by through-zero modulation within a single 12 HP wide module.

Everything starts with the exceptionally precise triangle-core voltage controlled oscillator (VCO) at the module’s heart. Through-zero linear frequency modulation (FM) enables rich yet pitch-stable FM sounds, by allowing the oscillator to run backwards into ‘negative frequencies’.

The resultant triangle wave is then processed by the through-zero phase modulator, providing a total phase shift range of 900°. Phase modulation offers an interesting alternative for FM, as it enables deep FM-type tones without actually changing the oscillation frequency.

The timbre of a signal is determined by its harmonic content. This full set of harmonics can be grouped into three main parts: the fundamental, even and odd harmonics. Generate 3’s harmonics generator separates out these three timbral ‘channels’. By adjusting their relative amplitudes, a vast array of different waveforms can be created, including but not limited to the classic sine, saw and square waves.

While the amplitudes can be adjusted manually, each timbral channel supports through-zero amplitude modulation, also known as balanced or ring modulation. When audio-frequency modulation signals are applied, the harmonics become ‘split’, enriching the spectrum.

In addition to all the usual analogue synthesis techniques, the extensive set of modulation options makes Generate 3 especially suited for exploring multiphonic synthesis: a monophonic source creating a complex timbre, much like throat singing, yet by electronic means.