Chris Groppi

Zu Audio Druid Mk 4/08 Speakers

High sensitivity speakers have had a following amongst the proponents of low power single ended tube amplifiers for a long time. Many of these speakers work well with these low power amps, but not necessarily with more typical amplification. Not so with these Zu audio Druids. While I am sure they still are wonderful with low power tube amps, they also deliver with more typical solid-state amplification. The Druid, made by cable and speaker manufacturer Zu Audio in Ogden, Utah, has had a cult following among many audiophiles. I was able to test the latest Mk. 4/08 version, released earlier this year.

A New Way to Plot Speaker Impedance: the Smith Chart

Impedance is the extension of the idea of electrical resistance to AC signals (like music). In high school, we all likely learned Ohm's law at some time or another. Whether we remember it or not is another story! Luckily, the refresher course is easy. Resistance is a way of relating voltage and current in a simple DC circuit.