Bassman

Notes for further expansion:

Scraped from: https://www.facebook.com/photo.php?fbid=1827988440586988&set=p.1827988440586988&type=3&theater&ifg=1

During November 1954, Fender introduced the newly designed 5D6 Bassman amplifier offering four ten inch speakers and was designed utilitizing two rectifier tubes. The 5D6 was a major departure from the earlier 5B6 Fender Bassman model. Designed by Freddie Tavares, longtime R&D man at Fender, the new circuit included two rectifier tubve and became known as the Dual Rectifier Bassman. Instead of the single 15" speaker, four Jensen Alnico P10R speakers were used. The circuit had two innovations: a fixed bias for the power tubes, which increased power in comparison to the earlier cathode bias design, and a cathodyne phase inverter, using half of the 12AX7 tube and allowing a third gain stage on the other half.

The first 4x10 Bassman amplifiers started with a batch of prototypes in November and December 1954, model 5D6. No schematic for the 5D6 circuit has ever been found, but Ken Fox and Frank Roy have created a few from originals, and copies are freely available online.

There appears to have been several different "Bassman" circuit topologies:

• 5B6
• 5D6
• 5E6
• 5F6
• 5F6A

These all need to be researched and for the information to be posted here...

-Zander