Looks like it might be headphones for me then...

I understand the appeal of not having to buy a headphone amp, but isn't the S/N likely to be worse on a power amp output? Also of course the sound you like from this amp is what it's like coupled to typical HiFi speaker loads, which may not be the same as with headphones.

Aren't there some STAX 'phones that run straight from speaker terminals too actually? I'm pretty sure I've seen some on eBay before now.

 

You should have a look at some studio phones. They tend to be made for running directly off a power-amp. At something like 400Ohms they wont explode from the amp as it will be designed to run at something like 4-8Ohms. Studios like to do this so they can have as many as they want running without worrying about there not being enough current.

You can run normal headphones off a power amp as well with a simple resistor network thing. I saw a diagram on Head-Fi ir somewhere once.

I had a pair of K1000's and I never noticed the S/N being a problem at all. Yes power amps make more noise, but that?s because they also output more power. The S/N ratio, is probably about the same as on a headphone amp.

and I don't think there are any STAX 'phones that run off a standard power amp as being electrostatics they need a huge voltage.

 

I said it on the basis that the S/N is generally worse, I think, for power amps than pre-amps, and I was assuming that a headphone amp would be more like a pre-amp. This may not be fair?

Hmmm... can't find any around at the moment but I'm pretty sure I've seen some STAX 'phones that run off speaker terminals, but they were old ones and not part of the current range. They may not have been electrostatics though (your point about the biasing potential is a good one).