I have a pair of Lambna Pros.. they have 5 pins, black in color. I don't know what the "regular" ones look like..
I am using mine with a new Stax tube amp, the 07t or something like that.. I feed it from my benz phono unit direct. way better than the 'black box' the lambna's come with. I'd like to know how much better the real expensive new Stax units are over these Lambna pros.. mine are about 14 years old now.