Below is a copy of the first Tubelab web page. It was first posted in July of 2003. It is here for historical information. It also reminds me that I change my mind too much. The principles presented in the first 2 paragraphs are still true. None of the amplifier projects mentioned in the later paragraphs were ever taken to the fully documented DIY project stage. Often the prototype was sold cheaply to someone who wanted to finish the mechanical aspect of amplifier construction. As I experimented further, I came up with better alternatives to these concepts. The A3 and grounded grid designs were rendered unnecessary by PowerDrive. I still want to explore those concepts further, but there are only so many hours in the day. I still have a warehouse full of tubes, and I have gone through 10% of them at best. I stopped searching for the "magic driver tube" when I found the 5842 / 417A tube. Now that my supply of these has dwindled, that quest continues again. Expect to see some data published in the near future. The vacuum tube car stereo amplifier remains a pet project for me. Many people think that the power supply is the hard part. It is not, you can hack a power inverter to get power. The trick is to find some tubes that are not microphonic, hence the 26E6WG military spec tubes. I have not built a car stereo amp that I am happy with yet, but I haven't had the time.