Protection Networks

Protection networks, power supplies, and other stuff not so interesting, but still needed.

You’ve read the section on how this came about? If not, go back and do so! Otherwise, take a look at the world’s first protection network that did not affect the sound AT ALL. Yes — it is the first one!

The design is very simple: passive sensing of current, then triggering a relay which removes the supply voltage from the output stage. As you probably know, the EC design uses one power supply for the voltage-amplifying stages and one for the power output, where all the large currents go. This separation made this protection scheme work. If not, big bangs would be heard …

The power supply also needed some care.

However, we did not make it difficult. The major point here was the use of small capacitors instead of the sluggish big ones everybody else used at that time. We understood that small capacitors in parallel were a better choice than single big ones.

The cabling was another issue — more on that later.