04-09-2023, 09:21 AM
Hi Peter,
Wishing and praying for peace throughout the world and in your region. Passover and Easter Blessings to you and yours!
Regarding RCA's use of Class B Amps, apparently, RCA discovered (or someone else discovered and RCA took credit for it like they usually do) tubes that could put out a motherload of power in "Class B". RCA used to claim that any output stage with a total harmonic distortion of less than 5% was "undistorted", so Class B was somewhat popular with them. For example , the "53" and 6N7 could put out 10 watts. The 49 and 19 tubes with 2V filaments, used in "farm" sets could put out 2W. 2 46s could put out a whopping 20W as opposed to 2 47 pentodes in class A push pull which could put out only 3-5W. And yes, they do NOT sound as nice as a Class A or Class AB1 Push Pull amp. RCA won't admit it but the 42 (and I think the 41) were Sylvania inventions, and Philco, a major car radio manufacturer, jumped on that bandwagon quickly. RCA was still into 2.5V tubes, and their version of the 42 was the 2A5.
Wishing and praying for peace throughout the world and in your region. Passover and Easter Blessings to you and yours!
Regarding RCA's use of Class B Amps, apparently, RCA discovered (or someone else discovered and RCA took credit for it like they usually do) tubes that could put out a motherload of power in "Class B". RCA used to claim that any output stage with a total harmonic distortion of less than 5% was "undistorted", so Class B was somewhat popular with them. For example , the "53" and 6N7 could put out 10 watts. The 49 and 19 tubes with 2V filaments, used in "farm" sets could put out 2W. 2 46s could put out a whopping 20W as opposed to 2 47 pentodes in class A push pull which could put out only 3-5W. And yes, they do NOT sound as nice as a Class A or Class AB1 Push Pull amp. RCA won't admit it but the 42 (and I think the 41) were Sylvania inventions, and Philco, a major car radio manufacturer, jumped on that bandwagon quickly. RCA was still into 2.5V tubes, and their version of the 42 was the 2A5.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55