BOSOZ question

I have finished a BOSOZ Board and was testing it out.

At 1000 hz, I put one volt in and at highest gain setting, get 5 or so volts out under no load.

I then put a headphone across the output (30 ohms dcr) and voltage output falls to a fraction of a volt.

Is this correct? I would have thought that the voltage drop would be less under a headphone type of load.

Any advise is appreciated. Thanx...