Hello PCBWay community, this is Dario. I am an Italian electronics engineer, with huge passion for audio and music.

I've been working for 5 years as Application Engineer in the Voice&Audio Solution team of NXP, now part of Goodix.

I've always been fascinated by vacuum tubes, some time ago I decided to start a small project with them, something simple and cheap, as a starting point. After some background study of audio amplifier design with vacuum tubes, I decided to design and build an headphone amplifier. I wanted it to be small, cheap but with excellent quality at the same time.

The outcome of this hobby project was a hybrid amplifier, with pre-amp stage made with dual-triode vacuum tube and power stage made by MOSFET. It can be powered with a relatively low voltage, something between 12.6V and 15V will be more than enough.

After manually soldering the components on the first prototype, I connected a 14V power supply and my Bose headphones. I was astonished and amazed by the quality of the sound, I could feel warm bass and crystal-clear trebles like I never did before with a pair of headphones.

What you see here is the third revision of the project, with re-arrangement of component placement and some improvements compared to the previous ones. As soon as new PCBs will be delivered by PCBWay, I'll also add some real pictures, it also looks really cool!

Soldering components will not be too hard, for people with a bare minimum of soldering skills. In the BOM you will find links for buying components on Aliexpress, the total cost will be definitely small.

Please feel free to download gerber files and documentation, to order PCBs and to copy/improve it, if you like!

I hope you will enjoy this amplifier, as I enjoyed designing and building it.

regards

Dario