In general, if you have the proper adapter cable to go from binding post to balanced headphone jack, you should be fine as long as you are careful with the volume pot.
There are typically two scenarios to be wary of:
1) too much gain/noise, in which case a series resistor on the outputs is typically used to knock down the output
2) it is a transformer couple tube amp, in which case you really want a resistor in parallel on the outputs otherwise there will be a "feedback loop" (not actually, but simpler to explain this way) that could potentially damage or destroy your amp.
If the amp has a headphone jack, chances are it already has one or both of these resistors in place.
Please do not ever use an adapter that goes from binding post to a TRS jack unless you know for sure that the amp has a common ground on the negative legs of the binding posts. Please do not get the robinette box which has been floating around for ages because unless you know what you're doing flipping one switch on that can damage your amp.
If your headphone only has TRS, then I highly recommend updating to a balanced cable. You can always safely use an adapter to convert the headphone cable from 4-pin to 3-pin, but this is not the case for amp adapter cables.
If you want an easy box that converts any amp output to a safe balanced headphone output, this is it:
https://store.hifiman.com/index.php/he-adapter.html
It is essentially both the series and parallel resistors mentioned above, forming what is known as an L-pad. Yes you could build one yourself for cheaper if you already have all the tools and knowhow, but the premade box is an ok value.
