Floating current source in cascoded output stage

[rtarbell]

A few weeks ago, I inquired in another thread about how the floating current source was implemented in one of Mr. Pass' amplifiers (see the attacheed image). Mr. Pass was kind enough to reply to me with the patent number, and he mentioned that the floating current source used a floating power supply rail (for instance, another secondary off of a transformer that is isolated from the main secondary).

My question is this: in the complete output stage shown, is the output voltage swing limited by the V+ and V- of the amplifier, or would it be limited by the power supply of the floating current source (because the floating current source "surrounds" the two main output devices)?

I would think that the voltage swing is limited by the V+ and V- of the main amplifier, but I wanted to make sure.

Mr. Pass came up with an excellent idea of using a floating power supply, and I am very interested in how this could be used in other amplifier applications.

Thank you!
-RT