Etonnant que personne n'en ai encore parlé.
Un nouveau VCO Quadrature made in Doepfer est en prévision.
From our point of view the main application is the expansion of the features of the frequency shifter A-126. It extends the frequency shift range to frequencies below 50Hz and allows thru-zero sounds. For this an adapter module (A-126A) is planned that allows to switch the A-126 between internal and external frequency shift (see small front panel picture). The external sine and cosine inputs of the adapter panel have to be connected to the sine/cosine outputs of the QVCO module. The switch on the adapter panel switches between internal and external frequency shift control.
Of course the module can be used even as a sine/cosine VCO. In the linear control mode typical linear FM sounds (including thru-zero) are obtainable. In combination with VCAs the basic principles of FM synthesis can be studied. But it has to be pointed out that for musically useful "real" FM synthesis the frequency and amplitude relations (the so-called modulation indices) have to be extremely accurate and this cannot be obtained with analog circuits. This is (and will probably remain) a digital domain !
Finally the module can be used as a 12dB VCF. The design is different from all other A-100 filters as there is so far no OTA based 12dB VCF available (only the Wasp filter A-124 uses OTAs but the special quality of this module are the digital inverters instead of operational amplifiers). [Vous devez être inscrit et connecté pour voir ce lien]