George Arthur Philbrick built the first commercial Operational amplifier, the K2-W. The company was first in Boston, MA: 1956 at 230 Congress Street, 1958 at 285 Columbus Avenue and 1963 at 127, Clarendon Street, Boston 16. In 1968 they were in Dedham, MA, Allied Drive at Route 128 where they still could be found in 1982 as Philbrick/Nexus Research, A Teledyne Company.

Some text from Joe Sousa in www.PhilbrickArchive.org:
The first commercial Operational amplifier was the K2-W op-amp. It was based on the amplifier used in the Philbrick modular Analog-Computor "black boxes ". That amplifier's basic circuit architecture, in turn, was probably inspired by an earlier amplifier designed by Loebe Julie (Dan Sheingold and Bob Pease, thanks for helping me with this information). The K2-W Operational Amplifier entered the commercial market in 1952. It performed mathematical Operations in analog computers. Soon after, the K2-W and its successors saw wide application in industry. The Analog Computer was one educational vehicle to familiarize the engineer and the engineering student, with Operational Amplifier techniques. GAP/R also took on a crucial educational leadership role with application guides and tutorials.

Over time, GAP/R was bought and sold, and existed under different names: Philbrick-Nexus, Teledyne Philbrick, Teledyne semiconductor, and currently TelCom Semiconductor.