Thinking about DC conditions, I wonder if using dissimilar metals for each connection, which adds a DC offset (as you've formed an electrochemical cell), might affect the distortion performance?
Also I've just noticed in the first post that a trick was missed - the connection to the banana wasn't made using banana plugs...
Also I've just noticed in the first post that a trick was missed - the connection to the banana wasn't made using banana plugs...