I am working on a design which must drive an audio output into 600 ohm headphones (aviation headsets). Normally, I would just use an off-the-shelf class D amplifier but I can only find ICs designed to drive 4-8 ohm loads. This could still work with an audio transformer, but would require a 75:1 winding ratio. The highest ratio I can find is ~55:1.
Can someone recommend a different design approach?