Has anyone had a problem with their HRD? All I hear is good stuff about
other peoples' but mine starts making a bunch of noise on the dirty channel
even as low as when on 2 or 3. Have taken to place where I bought it
twice - first time nothing was done, second time fixed it but quickly went
back to the way it was, which was and is really annoying.

Are there maintenance steps I should be doing with this amp or have others
had a similar experience?

Thanks for the help.