Power Supplies — Nelson Pass / 2001

Lots of people don't understand electricity, but they do understand plumbing. Hydraulics provides a good analogy in understanding basic electrical flow. Wire is a pipe. Water pressure is voltage. Water flow is electrical current. Lakes and storage tanks are capacitors. Diodes are one-way valves. Tubes and transistors are faucets. The entire power circuitry of an amplifier can be seen as a community water system. The sun, driving the weather cycle, deposits water on the landscape, and it collects in a lake behind a dam. The community draws water as needed through pipes. In the winter, the rain collects in the… More...

Like Peanut Butter and Chocolate — Nelson Pass / 2002

Pass Labs XA Series Power Amplifiers For over ten years, the Aleph series of single-ended Class A amplifi ers have received praise for their outstanding sonic defi nition, warmth, and smoothness; and have often been compared favorably with the very best tube amplifi ers. The Aleph topology achieves state-of-the-art performance with a very simple linear design, and is additionally one of the most stable and reliable audio amplifi ers in existence. A considerable number of audiophiles have found themselves bi-amping their loudspeakers, putting Pass X amplifi ers on the bottom for power and control, conjoined with Alephs on the top… More...

Build a MOSFET Citation 12 — Nelson Pass / 1981

Audio Amateur has published a number of projects modifying popular kits, usually Dynaco's. Obviously it is much less expensive to use the chassis and power supply, pots, connectors, switches, PC boards, and heat sinks that can be had for the price of a kit than to buy the components individually or have them made. Creating a one-off copy commercially typically costs as much as making 10 copies of the same item, because the dominant costs are design and set-up time which do not increase with quantity. Small wonder then that most technicians and designers who write for this and similar… More...