Even though the 20.6 update was only one circuit board, Levinson no longer provides the update.
To be clear, as far as I can tell by listening, there is nothing wrong with my 20.5s. However, as I said I love them and 16 years of Class A heat is a long time and a lot of wear on the caps, if not resistors. These amps cost $12,000 in 1990 (that's like $35,000 in todays $$) and even Levinson no longer builds amps like these are built.
I just want to get them checked out and get anything replaced that needs replacing before something goes wrong and does some damage to them. Other than my Magnum Dynalab, which I don't play very often, the 20.5s are the only component in my system that I have not replaced in the last 10 months.
Thanks, guys
Ed