Zen Variations 9 — Nelson Pass / 2006

In ZV8 we dipped our toes into the waters of power JFET transistors using the new Lovoltech LU1014D in a simple circuit. The focus of the project was on the JFET itself, and except for a cascode transistor the rest of the amplifier used only passive components. Here in four installments we will increase the complexity of the circuitry around the JFET with an eye toward distortion performance surpassing any of the Zen projects to date. Much of this project will make reference to ZV8 (AudioXpress, January 2006 and www.passdiy.com), which discusses the characteristics of the LU1014D power JFET and… More...

Zen Variations 3 — Nelson Pass / 2002

In Part 2 we developed a new active current source for the Zen amplifier. In this part, we create a power supply regulator suitable for the Zen amplifier projects. Previous versions of the Zen amplifiers had no power supply regulation at all, or used capacitor/inductor/capacitor "pi" filters to smooth the ripple on the DC supply lines. In keeping with our philosophy of simple-aspossible, we want to develop a supply regulation system which gives us good regulation, with low AC noise and a stable DC value. The need for a good regulator is obvious enough. As simple as they are, the… More...