Bulk metal foil resistor is very expensive but gained a lot of good words in audio application.
I thought you might have heard that there is a new type called the "Naked" foil. A lot of people claim that it has a very noticeable improvement over the traditional style, encapsulated type.
In order to see what's inside under the epoxy coat, I have cracked one and let's take a peep. :-P
After taking off the "black" coat, there is another coat covering the metal foil. It's obvious that it is used to protect the delicate metal foil.
So, you might ask, what's under the brown coat then?
Here it is,
Yes, the expensive metal foil resistor is now completely vanished. We can see the foil which is bonded to the brown coating.
OK, here is the real "Naked" foil resistor,
Sexy? I don't think so. :-P
How does it sound when comparing to the usual type?
It does show some merits, a little bit more open and relaxed but the difference is subtle.