Having built a number of vacuum tube output transformer-less (OTL) amplifiers in recent years, it seemed as though it might be a good idea to try combining older with newer technology and using both ...

This project was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality. The Power Amplifier section ...

Here’s a way of transmitting audio that makes it virtually impossible for someone else to listen in. Instead of sending radio waves bouncing all over creation, this uses the focused light of a laser ...