The K2-W vacuum-tube op amp has an LTspice-simulated open loop gain of 27,000. The modeled K2-W input impedance is >100 MΩ. The LTspice modeled result shows 1.00 nA of input current. Early SPICE ...

In 2008, Kendall Castor-Perry began an extended investigation into the effect that bypass capacitor selection has on analog circuit performance. Five years on, we’re re-posting this classic series, ...

As a service to our readers, we're providing the LTspice files used in Dr. Dyer's article on simulation of the 12AX7 and the K2-W vacuum-tube op amp. 1. The model for the K2-W is established as a ...

Previously on “Yet More…” – OK, that joke is wearing a bit thin. By the end of part 3 we had just got to the point of seeing that when we apply a current excitation to our modelled power supplies, the ...