Here's a discussion and demo of a 1967 Univox U-305r. They made this amp in two configurations - short and tall. They also seem to have made it with both 6973 output tubes and 7591. This version is the tall one with 7591 power tubes. There are other differences as well, which I'll touch upon in the video. This example has had nearly every cap in it replaced. The reverb tank has been replaced, but the speaker is the original Jensen C-15PS. New 3-prong cord added, selenium diode replaced, output tubes biased