Switched integrator (CB8871E)

Found in a1968’s Burr Brown documentation, this shield uses an integrated circuit from that time, which is uncommon today.

TPS54824 Synchronized Step Down SWIFT Converter
Mouser Electronics is stocked with Texas Instruments SWIFT Step Down TPS54824 Synchronized Power...
Audio Preamplifier (CB6479E)
Obtained from a 1996 documentation, this circuit uses common components and has a voltage gain of 200...
Two Time Constant Tone Decoder (CB6200E)
This circuit is from a 1980s documentation featuring two time constants for sound decoding. The...