I get a lot of top end audio amplifiers in the shop (everything from guitar amps to P.A. systems) that use the awkward quasi-complementary-symmetry output stage. The quasi-complementary stage was originally designed (according to legend) because it was difficult to build high power PNP transistors, so they had to fake the PNP side by using a pnp driver and an NPN output device (the 2N3055 still reigns supreme).
My question is....with MODERN semiconductor manufacturing methods, is the "quasi" even necessary? Certainly there should be a complement to the 2N3055...or is there? Does anyone have an inside track on this.
The quasi complementary symmetry circuit is an annoying circuit....not because it sounds bad...it just seems like a kluge. The true complementary-symmetry amplifier is...well...more symmetrical.
I've been in the business for over 45 years and can't figure out why the quasi complementary circuit hasn't died a necessary death.
Help me understand.
Eric
My question is....with MODERN semiconductor manufacturing methods, is the "quasi" even necessary? Certainly there should be a complement to the 2N3055...or is there? Does anyone have an inside track on this.
The quasi complementary symmetry circuit is an annoying circuit....not because it sounds bad...it just seems like a kluge. The true complementary-symmetry amplifier is...well...more symmetrical.
I've been in the business for over 45 years and can't figure out why the quasi complementary circuit hasn't died a necessary death.
Help me understand.
Eric