A new amplifier

I’ve been away from the world of hi-fi and DIY for a long time. Before I went back to school I started building a power amplifier designed by Nelson Pass, but I never finished it. Until now.

I feel as though I finally have my commute worked out, and the work routine under control more or less, and so I pulled out the bits a couple of weekends ago and got it all finished off.

Metalwork (the enclosure and heatsinks) are always the hardest part. In this case I used a mix of plywood and redwood strips, combined with a cheap extrusion and a couple of surplus heatsinks (originally one piece: cut in half on the table saw).

It came together pretty quickly. Self-tapping screws to hold the transistors down, and wood screws or machine screws for much of the rest. The amplifier draws a lot of current, and I was pretty nervous turning it on, but with some great advice from online, and a lightbulb as a current limiter, it all worked out fine.

The sound is great. It’s super-clear, and a pleasure to rediscover a lot of music. It’s also completely quiet: no audible hum or noise at all. If you want to learn more, Nelson provides information on another of his websites: www.firstwatt.com.