Since last year, I have been focused on building my own tube amplifier, especially using 300B tube in the single-ended configuration. I got more enjoyable moment when listening music through the tube amplifier instead of solid-state amplifier, especially with the 300B tube amplifier. The sound is more musical, more engagement to the music, and human voice alike compare with the solid-state amplifier. Previously, I also had experience using others tube such as 2A3, KT88, 6L6 and EL34, but I still believe the 300B is a holy grail of all tubes, so I stick to this choice. 300B tube is direct-heated tube (DHT) , meaning this tube heater also act as the cathode. In the single-ended amplifier, using DHT tube will potentially contribute the hum to the speaker. This is because the power supply voltage along with the noise feed into the heater tube and direct impact to the cathode itself. Annoying hum needs to take care. I took so many lesson when building several 300B amplifier before...
This is the following post regarding building the miniaturized DAC that should sound good, just like full-size desktop DAC. But the difference is in the small chassis. The reason for this is because in my opinion, a DAC unit is not to be shown as the main show unit in the audio system. So let it be hidden somewhere else at the back of the system and let the tube amplifier, speaker and source player as the part of the main show in the audio system. In this post, I will make another DAC using the components that what I have left in my bin. I think in this post, the description will be more in technical. I will try to explain the building concept for the good sounding DAC based on my experienced. This build will be more complex, harder to follow for beginner, but for some reason, I just want to do it. So, let's begin for this AD1865 miniaturized DAC build.