Bare wire....Tube connectors...bfa banana... get yourself a small butane torch and do some ultra high purity copper solder (careful not to set yourself on fire in pursuit of high fidelity)... Or go to an artist or jewelry maker and ask politely without looking like a Sheldon.
Word on the skreets is that lead solder could damage purity...screw up the electron, quark, boson flo, etc...