Yesterday afternoon, as a last resort, I removed the OPA627 op amps and reinstalled the OPA602's. After a night of repeating the breakin track from the Stereophile Test CD #3 the harshness is now gone. Go figure! This isn't a bad DAC, especially when you consider the $135 price tag. The bass and lower midrange are a bit more pronounced, and is about 5dB louder than my Scott Nixon tube dac, making it an especially good choice for anyone with bass shy speakers like Fostex single drivers and many horn speakers. The soundstage is more convincing than the SN dac - wider with a slightly better separation and isolation of instruments.