No connector is the best sounding. No connector, as in bare wire. Unplated copper spades would be my next choice, but you have to occasionally polish them for best sound. If you like the sound of silver, then bare silver spades. They say the oxidation on silver is just as conductive as the silver itself, but something tells me they would benefit from polishing as well.
Connectors
Have to go to spade connectors at amplifier Pass 350.5. What spade connector sounds the best? Silver, copper, or combination of the two also which brand of connector would you use. Have electrostatic speakers and vinyl is my source. All suggestions appreciated.