10w Amplifier Class A

It is in class A, and you can increase the low end frequency response by increasing the output capacitor. 4.7mF would be good. A class A amp won't chop part of the wave. The active device in class A is always conducting more or less. In class B it would chop part of the wave, but even then a second active device will handle the other half.

Thanks the bugger, the cap made a good deal of difference, I know what you mean about class B, adjusting the bias can make it class B but when both devices are pushing and pulling can that be true class A? My understanding is that one device did all the work for 360 degrees of the cycle and the other was an active current sink.

Yes, but remember, in class B the two transistors will never be conducting at the same time. One of them will always be switched off while the other is on. So 1 transistor handles 180dgs of the cycle and the other handles the other half. But notice here that both transistors are conducting, all the time, and they never shut down completely. This means they both work in the linear part of their characteristic which defines the class A. Nothing else should concern you about the topology, whether it's single ended or with 2 active devices, as long as they're both always conducting it's class A, if one is conducting while the other is off it's class B and if one starts conducting before the other completely shuts off, it's class AB.

It's going a little into cutoff, but that's easy to fix, just decrease the input a little. And remember whenever you encounter a frequency response problem, first check your capacitors and inductors. They are frequency determining/dependant components.

It looks like the JLH without the bootstrap