just completed another headphone amp using the famous 300B as the power tube. The client is a very young and nice guy. He is studying and working part-time. But he wants to get the best and affordable headphone amp, and it is my job to fulfil his dream.

All the transformers are Tango ISO since the may be the best but still reasonably priced items that we can get from Japan. The design of circuit is simple and no interstage transformers are used due to limited budget and size of the unit. High quality parts such as Elna and Jensen copper film caps are used to ensure best attainable performance.

He has special concern on the appearance of his toy and we had a lot of discussion on the planning of this project. The position of transformers and tubes are finalised and the drilling and cutting began. It took one week to get it completed and the operation test proved to be outstanding. All the measured readings are within the designed value, and the residue hum is very low. I was quite worry about that too much hum may induce due to the positioning of transformers and tubes but it turns out okay.

To hear is to believe. His AGK headphone sings and there is black silent while no music is playing. He loves it.