Well, I am not very good at soldering, so I think working with Ron is great and has a lot of advantages. He is very experience with opamps and he keep a tap of what is coming up new . He is a very nice guy to work with. He sent me four sets and allow me to audition them and sent whatever I don't want to keep back. I really like the Class A socket where you can put the opamp into. The difference between the 1678 and the 55002 is that the 1678 gives a cleaner, more natural sound and the 55002 gives more bass and a little more body. So it depends on what your flavor is. if you have a bright phone, the 55002 will taper it a little bit, but if you have a phone like the LCD2 that already has a lot of base and body and the mid is a little recess, the 1678 will do great by giving it a little brightness (most of the time, clean, natural sound gives the impression of brightness) but will not compromise the bass and the body of the LCD2.
