Xen-Arts has introduced IVOR2, a major update to their free Ivor microtonal virtual analog synthesizer for Linux & WIndows.

IVOR2 is designed to be microtonal sound-designer’s virtual analog synthesizer, with a workflow tailored to microtonal synthesis. It’s also designed to be an educational tool for learning about subtractive sound synthesis and musical instrument intonation (microtuning and xenharmonics).

IVOR2 is a two-oscillator subtractive, FM, XFM and RM synthesizer that features full-controller MIDI Pitch Microtuning using MTS (MIDI Tuning Standard), where any MIDI Note Number can be freely microtuned to any desired pitch across the MIDI range. This lets you explore the vast possibilities of composing music with alternative intonation systems.

New features in version 2 include:

MOD-GEN – a generalized hybrid Modulation Source Generator, which includes an envelope generator that can be switched between an ADSR or a Graphic Envelope Generator, and an LFO that can be switched to run at audio-rate: the ARO. The IVOR2 VSTi features eight total MOD-GEN of this type, which are used for modulating the Phase or Pulse-Width Modulation (PWM) of each oscillator waveform, the range of Phase & PWM, Crossfade Modulation (XFM), Filters, VCA and Pitch.

A powerful synthesis feature of the IVOR2 VSTi, is that when the MOD-GEN LFOs are switched to the ARO mode, they are capable of generating additional sideband spectra in the signal, resulting in complex, expressive and evolving timbres. Additionally, the frequency ratios of each ARO may be configured by loading a Partials File (TXT), which enables basic tuning and timbre correlations of the generated sideband spectra, especially where sine-waves are being used as the modulating waveform.

Oscillator A & B Pitch Modulation Polarity – All pitch-modulation sources may be configured so that the pitch of each oscillator can be modulated in a common direction and polarity, or the signals inverted for modulation in opposite directions, as well as switched to a static setting without modulation when, for example, using the MIDI Pitch Wheel Controller. When the modulation control signals are inverted, the phase of the modulation sources routed to each oscillator’s pitch is effectively at 180°.

Each of the below pitch modulation sources may be configured to modulate the pitch of the two oscillators in either a common direction and polarity (0° phase), or otherwise, in opposite (phase inverted 180°) directions:

• Pitch Bend Controller
• Mod-Wheel Vibrato
• Pitch Mod-Gen
• Harmonic Mod-Gen
• Crossfade Modulation (XFM)

Crossfade Modulation itself is a common feature of contemporary synthesizers, however, this instrument enables a unique variant of the technique: partials-file controlled audio-rate modulation between two oscillator sources using a dedicated MOD-GEN, which is capable of generating intonation-related sideband spectra, thereby creating interesting sonic relationships between the microtuning and timbre of the instrument, and especially in the most simple XFM case scenario of using sinewaves with different pitch transposition offsets.

Phase & Pulse-Width Modulation with MOD-GEN – Unique to IVOR2 are the versatile Phase & PWM Sliders and MOD-GEN routing options that replace the single control in the original version.

Each oscillator has a pair of these range sliders, which can be set to fixed values, and MOD-GEN source routing selectors that can optionally override the sliders and their targets modulated with dedicated MOD-GEN.

RM-Phase-PWM – In more typical synthesizer Phase and PWM modulation scenarios, the range of the modulation is set to fixed values. With IVOR2 the range can be fixed, or alternatively modulated by a MOD-GEN to create a huge variety of real-time timbral variations, sweeping notching effects, as well as FM timbres when running the LFO in a partials-file controlled audio-rate modulation (ARO) mode.

With these new phase and pulse-width modulation features, the IVOR2 VSTi offers new options for microtonal and xenharmonic sound design.

IVOR2 is a free download from the Xen-Arts site. Audio demos are available at the site.

If you’ve used IVOR2, share your thoughts on it in the comments!

via Jacky Ligon