So, for fun today, I built a monophonic tube amp from scratch. This is the simplest tube amp in the world; it uses one tube, which is both a half-wave rectifier and an output pentode. It puts out just under one watt, under ideal circumstances. Not much power; it would need very efficient speakers to have loud volume. But it is quite nice for a desktop setup; no need for blasting my eardrums. The tube is a 117P7GT, made by Tung-Sol in the USA in about 1945 or so. I bought six of them in surplus WWII cardboard boxes for 99 cents each a few years back. The amplifier design is not mine; it comes from a book called Practical Amplifier Design, by Robin and Chapman, around 1940 or so. I ordered the parts (very inexpensive) from Allied Electronics a week ago. I added a fuse and an isolation transformer to the design for safetys sake; the original design was straight to the house mains, a hot chassis design and a real deathtrap if one were to become a better ground than the chassis. With a simple isolation transformer, its perfectly safe. I am now going to add a second channel to make it stereo, and then think about how I want to enclose it more permanently. This is geek fun. For me, anyway.
Posted on: Sat, 30 Aug 2014 16:59:16 +0000
Trending Topics
Recently Viewed Topics
© 2015