NPN only class AB power amplifier

[Benito]

I was wondering if it was possible to use two identical NPN transistors instead of an NPN-PNP pair.
I was thinking that if you could flip the signal, apply the original signal to one NPN and apply the inverted signal to the second NPN and gave both a slight bias current, you could do it.

I just wanted some feedback as to the feasibility of the idea.
If it won't work, I guess I'll order some PNP transistors or just make a class A amp.
Thanks in advance!


P.S. I'll add some schematics later if needed.

 

[audioguru]

Quasi-complementary amplifiers were made in the 60's. I still have one. They used NPN output transistors and complementary driver transistors.

The MC3317x and MC3407x opamps have all-NPN outputs. The circuit is very complicated and relies on the good matching of the transistors and their matched temperature inside an IC.

Class-AB amplifiers use NPN and PNP complementary outputs. A class-A amplifier sounds the same but heats your entire neighbourhood.

 

[crutschow]

The first circuit I saw of one was in the old GE Transistor Manual.

Here's an example **broken link removed**.

Edit: I also built (and am using it now to power my PC speakers) a Dynakit Stereo 120 60W/channel stereo amp way back in the 60's which used a very similar circuit. Still sounds great.