High Purity Audio Sine Wave Generator

Oscillator (provisional)
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Output Buffers
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1. The oscillator is a biquad made up of two integrators and an inverter.
2. The peak of the sinewave is sampled, integrated and applied to a variable resistor to control the amplitude.
3. The sample pulse is derived from the quadrature waveform.
4. Pulse position is adjusted by a preset pot and there is phase advance at high frequencies.
5. The comparator outputs are open collector and pull down from +5V or 0V to -5V.
6. The OTA control inputs are referenced to -5V. Momentary short to ground will melt/vapourise the chip.
7. Probably best built on three cards, osc, trig, output and connected to a mother card.

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