There was a hint of doom when all I heard over at the amp was a serving of fuzz. That shouldn't happen because the Dude is definitely not a fuzz unit. So the diagnosis took place beginning with the cables. The joints could take a toll after repeated use but that was not the case. A quick twist over at the guitar end revealed no crackling; the guitar's input jack is still in good health. The amplifier was then suspect. Some channel switchings revealed no faults either.
The mind boggled for a while until I recalled the last thing I did to the pedal itself before I started playing- battery installation. It was a fresh battery in there so what could really be the fault? Sherlock Holmes once said if you eliminated all possible suspects, whoever's left to be dealt with is the culprit no matter how remote or improbable it could be. A quick battery replacement confirmed the theory immediately; the battery was criminal all along. So there we have it, a dead battery in a fresh setting. Never overlook a suspect even if it's deceivingly pleasant. Case closed.