50EH5 Single-Ended Tube Amplifier
Gio Militano 
Page 1: Background, Single Ended Amp Design
Page 2: Construction, Sound
Construction: 50EH5 Tube Amp
For myself, I always find that the most time consuming and difficult portion of a tube amp project to be the enclosure. In an effort to keep costs down, I constructed the enclosure from an old beat up cooking pan. A couple pictures of the aluminum pan are shown in Photographs 2 and 3 below.
Photograph 2: Top View of Aluminum Cooking Pan
Photograph 3: Bottom View of Cooking Aluminum Pan
As you can see, the pan was fairly beat up and rusty, but that was taken care of with a little sand paper and paint. Photograph 4 below shows the chassis after sanding and most of the drilling. RCA inputs, pot and tubes were kept close together and away from the power supply.
Photograph 04: 50EH5 Tube Amp Under Construction
Total costs for this project came in at well under $15US. The only new parts used are two resistors, two tube sockets, two RCA jacks, four binding posts and four rubber feet.
Photograph 05: 50EH5 Tube Amp Wiring
50EH5 Tube Amp Sound
Despite the small size of this little single ended amp and the flea power output (1.3W) the sound is good! I generally like single-ended amplifiers. While the amp cannot deliver full bass extension due to the small audio output transformers used, the rest of the audio spectrum is very clean and clear. The imaging from this amp is very detailed and has good depth. My CD player drives this little amp to almost 1W, and not into clipping. Given the very limited power output, this little amp will need to be mated with efficient speakers. I really like the midrange and high frequency response from this little amp and I use it to power efficient Radio Shack 40-1310 Super Tweeters as part of a bi-amped system.
Photograph 6: Front View of Finished 50EH5 SE Tube Amplifier
Photograph 07: Rear View of Finished 50EH5 SE Tube Amplifier
UPDATE October 2008: We got an email from Alan in Eastern Canada who also built a similar 50EH5 tube amp using a Fleetwood console. For information and photos of Alan's project, see the DIY 50EH5 / 25EH5 Tube Amplifier thread on the forum.
Background, Single Ended Design |
[ 1 | 2 ] |