Waveform producing system

Abstract

In a waveform producing system for use in, for example, an electronic musical instrument, a tone generator circuit and/or a tone control circuit including tone keyer circuits, each or either one of said tone generator circuit and said tone control circuit comprises: pulse generators associated with key-actuated switches, respectively; waveform memorizing means having at least one row of voltage dividers of which the division ratios are preset in characteristics corresponding to either the tone waveforms, the tone envelopes or the depression speeds of the key operated by the player of the instrument; sequential memory read-out means connected to the respective voltage dividers; and pulse generators thereby providing an enabling signal sequentially to the individual dividers every time a pulse is inputted from the pulse generators to read-out the memorized waveform in the form of a modified audio signal at the output side of the circuit. The memorized waveforms can arbitrarily be sampled (scanned) out by using a sampling circuit in the read-out means, thereby providing variations in the modified audio signal. The tone control circuit enables the tone level control in conformity to the depression speed of the key and tone envelope control without the need to employ the conventional charge-discharge circuit requiring a relatively large capacitance capacitor, and makes it easy to carry out circuit integration.