Spectral Audio ProTone

Spectral Audio ProTone Image

The ProTone is a true analog synth from the mid-nineties for the modern MIDI studio. It is monophonic and features two analog oscillators, a beefy resonant filter, flexible LFO, MIDI and CV/Gate control, and a simple intuitive hands-on layout with every control parameter accessible from the front panel knobs and switches.

Each oscillator features saw and pulse waveforms with independent waveform selection, tuning and level. White Noise is also available from VCO1. The oscillators can be sync'd and Ring Modulation can also be dialed in. The filter section allows for either high or low pass filtering and 12 or 24 dB/oct slopes with the usual cutoff and resonance knobs. A fairly standard ADSR envelope can be applied to the voltage-controlled amp, but there's only a decay envelope (Accent) for the filter. The LFO is quite flexible, with six wave shapes plus random, noise or external input. The LFO can be set to modulate VCO1, VCO2, Pulse-Width on VCO1, filter cutoff and panning. A few remaining controls include a Panner, and Slide (portamento) effect.

The ProTone features MIDI I/O and traditional CV/Gate I/O for use with vintage gear. A little too much like vintage gear, however, the Pro Tone does not have on-board program memory. But with such a basic synth architecture and no hidden menus or parameters, the ProTone is a hands-on tweaker's synth - full of fat analog bass and synth sounds with a squelchy filter and competent LFO. Additional features include external VCO and LFO inputs, MIDI controlled volume and frequency cutoff, velocity sensitivity, and stereo outputs. The ProTone makes a cost effective, reliable and unique alternative to many other older vintage dual-VCO analog mono-synths.

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Rated 2.93 (150 Votes)

  • Check Price
  • The link above will take you to an eBay search for this synth to see active listings. If you don't find it there, try looking in our forum marketplace or post a wanted classified.
  • Specifications
  • Polyphony - Monophonic
  • Oscillators - 2 analog VCOs (Sawtooth and Pulse Waves); White Noise Generator; True Ring modulator
  • LFO - 1 (Rectangle, Impulse, Triangle, Sawtooth, Sinus, Noise and Random); Wide LFO Range: 0.005 ... 3800 Hz; LFO Targets: VC01, VC02, Pulse Width of VC01, Cutoff and Panorama
  • Filter - High and Lowpass Filter with Resonance, Selectable 12 or 24 dB per Octave, Accent (Decay Envelope for the Filter)
  • VCA - ADSR
  • Effects - Slide (portamento)
  • Memory - None
  • Keyboard - None
  • Arpeg/Seq - None
  • Control - MIDI In/Out, CV+Gate In/Out
  • Date Produced - 1996-2001
  • Resources & Credits
  • Images from Spectral Audio

    Reviewed August 2008.

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