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. Features include a minimum 10,000 to 1 sweep range, on-chip control of resonance, differential inputs, high control rejection, and minimized external components. The SSI2144 will operate on supplies as low as ±4V, and improvements include lower noise, significantly better control feedthrough, and more consistent unit-to-unit performance of the resonance control. Pin connections were revised for PCB layout ease. Most importantly, the SSI2144 preserves the coveted sonic character of the SSM2044.

Features:

• Classic Analog Synthesis Timbre
• On-Chip Resonance Circuit Improved for More Consistent Control and Performance
• ±4V to ±16V Operation
• Pin Connections Optimized for PCB Layout
• Differential Inputs
• Large Sweep Range - Typical 20,000 to 1
• Low Feedthrough on Both Control Ports
• 16-Pin SSOP Package with Minimal External Components