Tas, sorry for the confusion on the cap value. Too early in the morning! My comments on replacing the electrolytic with a small value film cap still apply, but the 470 µF value increases my suspicion that this is really a power supply filter rather than an output coupler.
One final comment. Just because a particular part like a Duelund capacitor has nearly unanimous praise does not mean that it will be an overall improvement in a particular application. For example, many years ago I made the mistake of buying a Threshold FET 10E phono stage based on reviewer recommendations. It turned out it had a large nonpolar electrolytic capacitor on the output so I figured I could improve the sound by replacing the electrolytic with a film capacitor. I tried a number of popular capacitors for that day, all of which made significant changes in the sound but overall I kept returning to the cheap electrolytic as the best sound for that particular preamp. It is quite possible you will find that the 470 µF electrolytic used by the manufacturer has some qualities that you sacrifice with a replacement film capacitor. I'm not saying that to discourage you but you need to go into this with your eyes open.