Actually Paul used the analogue connection.

Your idea about a second opinion has a fatal flaw. He has different hearing. Where his hearing is at could be different than yours. Hearing loss is different for everyone. We all have lost some of are hearing. We also perceive sound in a different way from one another.

Removing sight from the equation is the key. Using your ears is the only honest way to tell if there is a difference. Sighted tests will always be biased in some way. Not knowing which player is playing and using only your ears is the key. This way your basing everything on what you hear. With no bias from knowing which unit is playing.