Operational transconductance amplifiers

Texas instruments has discontinued the DIP-16 version of the LM13700 so they are getting harder to buy. You can use a SOIC to DIP adapter board to fit a SOIC-16 LM13700M/LM13700MX chip into a DIP-16 footprint. There is also a clone of the LM13700 called XD13700 made by a company called XINLUDA that is still manufactured in a DIP-16 package.

Through-hole

SMD