Here will be found Papers attempting to answer questions regarding our products and their design. You can read them here, or download them and read them later offline. Below each paper is a download link, and just to the left of it is the title of the paper, if you click that title they will enlarge to see better.

Below is a list of papers we felt some would benefit by reading.

The photo above shows the three basic types of 6Y6 beam power pentode vacuum tubes. The left is the 6Y6G or original 6Y6 and its ST-12 glass envelope, in the middle is the 6Y6GT in the T-9 glass envelope which is a lower power version limited by its screen grid, and on the right is the 6Y6GA "big bottles" in the T-11 glass envelope, there is also a 6Y6GA in the T-9 glass envelope. All of these "styles" or types of 6Y6 tubes sound very much the same with minor differences, within each type between matched pairs they tend to have there own sound. Any UA2.5 purchased from us comes with a matched pair of 6Y6 tubes, and they could be any of these three styles or types.