the leonardo set amp

Vacuum and iron make real magic...

This amp is very special to me. It concludes, in one single implementation, a long search for a path to the sound reproduction that makes me feel really good.

True, single end is considered inferior by many, and, equally true, the few watts of output power are considered a joke by others. Nevertheless, this is what makes this hobby so rewarding; there is plenty of room for us all.

The circuit design is as simple as it can get – two triodes and two transformers. I’m not aware of who tried it out first, but my guess would be that the circuit is more than 70 years old. You can find it in the classic Radio Designer’s Handbook, and a thorough treatment and evaluation is presented by Matsunami Kiyokazu in the Japanese MJ magazine (7, 1997).

As expected, a number of constructions can also be found on the Internet; e.g. by Andrea Ciuffoli, Alessandro Galavotti, Benny Glass, Simon Shilton, to name a few. Theirs and other similar constructions represent variations on the same theme – a superior SET design. By the way, my chassis layout is borrowed from Mr. Ciuffoli, who deserves credit for his versatile layout.

Due credit is also given to Per Lundahl, who produces the magic iron that brings musicality to my amplifier. The musicality is no less than stunning. The voices of my favorite vocalists can bring my eyes to tears. The emotional qualities outperform any amp I’ve ever listened to.

I can appreciate though, that if your own track is more like heavy rock and stage music, this amp may not be your first choice. I can assure, however, that if you have a pair of good speakers, Metallica’s Black Album is a real joy – so stay tune…

[ previous ] [ back to top ] [ next ]