Anyway this is a Dynaco Dyna PAS 3 preamplifier. That is to say it is my Dynaco Dyna PAS 3 preamplifier. Also, my cat.
It is in good, original working condition. However, there are lots of mods you can do to "improve" it's function. Some of them even help.
Since it is working perfectly well, I've decided to mod it. My mods are based on this article from the mid 90's http://www.normankoren.com/Audio/Spice_preamp_2.html
The layout of that page is appropriately old timey. Anyway the two main circuits go from a 4 tube layout to a 6 tube layout
however, vacuum tubes require little electric heaters to work, and that draws a lot of current. so much current, in fact, that you have to upgrade the power supply. that's a lot for a beginner's project, so I redesigned the circuit slightly to use mosfet transistors in the two added stages.
