On May 7, 6:19*am, DrRick wrote:
Class AB2? With a single output tube? How did the designer accomplish
that? I will pick up a copy of the magazine if Barnes & Noble has it.
Class A2 I can understand, but I am unaware of any design methodology
in which one could achieve class AB2 (or B) operation with a single
output device.
Peace,
DrRick
Bret L;906635 Wrote:
The latest AudioXPress has on its cover a stereo amplifier using one
4D32 tetrode in Class AB2 per channel as an output device.
Why do people persist in acts that aren't just stupid but willfully
destructive?
The 4D32 was neither designed for nor is it really any good as an
audio amplifier. Its only use today is .........................
--
DrRick
You need TWO tubes for class AB because the term class AB infers that
one tube of the pair cuts off during each wave cycle before the other
tube reaches a crest in the peak tube current when working at power
near clipping.
The data for 4D32 is at
http://www.mif.pg.gda.pl/homepages/f...138/4/4D22.pdf
Its a grunty tube with Pda rated at 47W, and with RLa-a = 3k, you get
112W in class AB1 using two in PP.
I recall AudioXpress had a class A2 SE amp desogn some years back
using one lone 6550.
Patrick Turner.