Tonetta Blue is a virtual eight-voice polyphonic synthesizer. The plugin features a semi-modular synthesis engine with dual oscillator modules, a pair of multimode filters, four envelopes, and multiple LFO modules. Another standout feature is the “Curve Mod,” which is essentially an LFO with a customizable waveform shape.See also: Free Synthesizer VST Plugins
The synth features two types of oscillators. The first one, called “Fat Oscillator,” delivers a layered timbre reminiscent of the classic supersaw. It is intended for fat lead sounds, strings, and pads. The second module is called “Dual Oscillator,” and it is a relatively standard dual subtractive oscillator with nineteen different waveforms.
The filter section also consists of two modules. The first one is based on the OTA-style filter design with six modes. The second module includes a state-variable filter and a ladder filter.
The raw oscillator sound passes through the filters first (oscillator one goes through filter one and oscillator two goes through filter two). Further down the signal path, the user can modulate the filtered sound and feed it through the built-in convolution reverb. The reverb module includes six different impulse responses, ranging from a small studio to a massive hall.
Tonetta Blue features a dual-panel user interface. The front panel is where you’ll find the main modules, like the oscillators, filters, and modulation sources. The second panel hosts the modulation routings. Thanks to its dual-panel interface, Tonetta Blue remains clutter-free and easy to operate even with more complex patches.
One minor caveat is that the plugin doesn’t feature a built-in preset manager (UPDATE: this feature was added in a recent version). The ability to save presets internally is always handy, especially with more advanced semi-modular instruments like Tonetta Blue. Of course, you can always save the current patch using your digital audio workstation’s preset storage.
It’s also worth mentioning that the developers provided a well-written user manual with detailed documentation about the synthesizer’s features. This isn’t always the case with freeware plugins. If you’d like a head start when using Tonetta Blue for the first time, keep the user manual handy as it provides quite a bit of insight into the plugin’s workflow and design concepts.
Tonetta Blue is available for direct free download from the Flanders Tech website. No sign-up is needed and the plugin doesn’t require activation, either. The software is compatible with 64-bit VST plugin hosts on Windows.
UPDATE: Tonetta Blue was recently updated and it now features a simple preset manager.
More info: Tonetta Blue (34.3 MB download size, ZIP archive containing EXE installer, 64-bit VST3 plugin format for Windows)