Some Audio and other Articles/Projects on Vacuum Tubes or Valves. Also he has made Online Calculators .. Bias Tool, Gain Tool and Low crossover cap. 
Vacuum Tube-G Pages from Peter
Some articles written by Alan Kimmel, as it did in the years 1993 to 2004 on the original Tube Labs.
- The Choke Assisted Mu Stage
- Why use the Kimmel mu stage
- 7 A few variations of the mu-stage
Related –
Welborne Labs – Wide assortment of DIY components, kits and factory assembled hi-fi gear.
TubeLab – Dedicated to advancing the state of the art in affordable high end audio.