Design analysis of the K2-W Vacuum Tube Op Amp’s design and operation reveals the mad science that created a commercial revolution in 1950s and 1960s analog computing. Op amps played a critical role ...

After a brief review of the history of the K2-W vacuum-tube op amp, an LTspice model is used to create its schematic in preparation for SPICE simulation. The availability of hierarchical blocks for ...

You could buy a cheap amp for $140, like I did. I got a Pioneer VSX D209 for that, with sales tax 6.5%. Sounds decent too.

Operational amplifiers (commonly called op amps) are a ubiquitous building block for designing electronic circuits. Today, these devices are fabricated as small integrated circuits, but the concept ...