Dual ADSR and LEO/NOISE modules - for the NEW Elektor synthesiser

2-24 — elektor february 1982 dual ADSR and LFO/NOISE modules As with the devices used in the rest of the synthesiser, the Curtis envelope generators require very few additional components. Another advantage is that the circuits do not require a great deal of calibration. As can be seen from the circuit diagram in figure 1, the two attack-decay-sustain-release (ADSR) gen- erators are identical, therefore it will be sufficient to describe just one in detail. Pins 9, 12, 13 and 15 of IC1 are the control inputs. The voltage levels applied to these inputs determine the duration of the attack, decay and release times and the sustain level. In this respect the module differs a great deal from the circuit used in the FORMANT synthesiser. The latter is not suitable for polyphonic operation using the stored preset data scanning method. dual AMR and LFO/XOISE modules . for the NEW Elektor synthesiser The NEW Elektor synthesiser can be completed by the inclusion of the two modules described...