Integrated Circuit - AS3320, Multi-Mode VCF, Alfa, 18-Pin Dip
The AS3320 is Alfa’s version of the CEM3320 IC. The AS3320 is a high performance voltage controlled four-pole filter with on-chip voltage controllable resonance IC. The four independent sections may be interconnected to provide a wide variety of filter responses, such as low pass, high pass, band pass and all pass. A single input exponentially controls the frequency over greater than a ten octave range with little control voltage feedthrough. Another input controls the resonance in a modified linear manner from zero to low distortion oscillation. For those demanding applications, provision has been made to allow trimming for improved control voltage rejection. Each filter section features a variable gain cell which is fully temperature compensated, exhibits a better signal-to-noise ratio and generates its low distortion predominantly in the second harmonic. The device includes a minus two volt regulator to ensure low power dissipation and consequent low warm-up drift.
Integrated Circuit - SSI2140, Multi-Mode VCF, Sound Semiconductor
The SSI2140 is a new-generation voltage controlled filter that provides four highly-configurable variable transconductance cells for a wide variety of pole and mode combinations, and adds significant new features.
Integrated Circuit - SSI2144, Ladder VCF, Sound Semiconductor
The second of two legendary SSM filter updates, the FatKeys™ SSI2144 is a dedicated four-pole low-pass ladder filter with on-chip resonance control. Original designer Dave Rossum did a number of performance updates such as lower noise, improved control feedthrough, and logical pin grouping but otherwise left this sweet-sounding VCF alone. The SSI2144 reprises the SSM2044 of legacy chipmaker Solid State Micro Technology, which many believe to be the best-sounding analog synthesis filter IC ever produced. Based on Dave Rossum’s patented classic improved ladder topology, the SSI2144 allows rich tonal characteristics that showcase the very best attributes of subtractive synthesis. The SSI2144 uses the same internal circuit as the SSM2044 but incorporates improvements by the original designer and takes advantage of modern process technology.