Yet Another Composite Chipamp Topology...

[DPH]

I realize that you're looking for compactness and simplicity, but using Black's feedforward correction really only makes sense (from a complexity/cost perspective) when you have a low-power ultra-linear amplifier actively correcting a high-power less-than-perfect amplifier.

What you have when you gang any of these chip amps together is a "high-power" less-than-perfect amplifier correcting another "high-power" less-than-perfect amplifier. In other words--a different mindset/plan of attack should be considered such as parallel, shoot-through biased chips, or a more conventional op-amp driving the outer loop.

Unless the goal is just to play around with topologies, whether or not they're targeted to some significant positive effect.

 

[jackinnj]

My comment wrt the shortcoming of Ovation models (and the efficacy of the compound topology) notwithstanding, here's a Bode using TINA:

 

[Capt Grogg]

output of U2 not connected to 15 ohm?

 

[linuxguru]

Yup, output of U2 has to be connected to the junction of C3 and R7 in post #22. Nevertheless, it seems to be barely stable even without the feed-forward from U2, which is a surprise. Perhaps the TI models are too optimistic wrt to stability.