The instrumentation amplifier in this picture is of the OPERATIONAL AMPLIFIER-type. In the case of Tube cases, linear amplifier will be delivered. In order to be more specific, this instrumentation amplifier is one of the types of Operational Amplifier devices.
MAX4125EUA+ Features
MAX4125EUA+ Applications
There are a lot of Maxim Integrated MAX4125EUA+ Instrumentational OP Amps applications.