Audio Research Reference 150 severe distortion

My Reference 150 is emitting severe distortion in both channels. I checked the bias of the K120 tubes and one tube in both channels is reading as low as 20, rather the the standard 65 range.

Does anyone know of a possible fix that will not involve me shipping the amp back to Audio Research?

Both bad tubes are less than 3 months old.

I gotta play my Liberace Christmas music!