2. amps-preamps
  3. 1107054599

Are tube amps class A ?

I understand transistor design but I'm a tube newbie... I've owned some CJ gear for 2 years now. When I think about amp classes it all comes down to bias current and switching. Are all tube amps essentially class A biased or is there still the concept of A/B ? I have an older tube design book somewhere but I'm thinking someone here will know.
btrvalik
4 responses Add your response
herman
2,216 posts
 
You can bias a tube to operate class A, AB, B, or C just like a transistor.

Any amp you can build with an npn transistor has an equivalent that can be built with a tube. The big difference is there is no complementary device for a tube like you have with npn and pnp transistors.
twl
3,251 posts
 
Single-ended Triode amps are Class A by definition.
btrvalik OP
61 posts
 
I have a CJ MV60 ... is it AB in ultralinear and A in triode or is it always AB?

thanks
Bruce
herman
2,216 posts
 
It is a push-pull amp biased AB.

A push pull amp can be biased A, like VAC's 300B amps, but CJ is AB.
Log in to respond
More to discover
80x80
Peavey 3609520
Peavey IPR2 3000 Power Amplifier PEV03609520
80x80
Gemini AS15TOGO15
Gemini AS-15TOGO 15" Portable PA Loudspeaker GEMAS15TOGO
80x80
Balanced Audio Technology VK80t