For some time now, analog synthesizers, especially in modular form, have experienced a real revival; as a result, even special synthesizer ICs were reissued, for example some components from the former manufacturer Curtis (CEM 33 xx series), the are now being manufactured by OnChip Systems in Latvia. The Californian manufacturer Sound Semicondutor Inc. takes a different approach: Its designer Derek Bowers has designed an integrated 1V / octave VCO from scratch.

Building a stable 1V / octave VCOs is enormously facilitated with the SSI 2131.

When Offshoot of the recently released SSI 2130 Sound Semiconductor is now bringing the smaller SSI 2131 out. The VCO has a range of octaves and is based on a current-controlled triangle generator with a temperature-compensated exponentiator; from the triangular waveform, it generates sawtooth and square waves with a variable pulse / pause ratio (PWM). On the sine shaper and the mixer VCAs of the SSI 2130 (in the little maker-friendly QFN 32 – housing) he has to do without, as well as the through-zero frequency modulation, which is sometimes required for FM synthesis, in which the phase of the output signal is reversed with negative modulation.

For this it comes in the SO 1, 27 mm leg spacing supplied. The manufacturer has not yet announced a price, but it should be in the single-digit euro range, as the more complex SSI 2130 costs around 7 euros. The SSI program also includes other delicacies, such as a worthy successor to the SSM 2044 filter ICs or a universal quadruple VCA Block.

(cm)