Durability of Mark Levinson 20.6

Caps at 20 years if it is still doing well.
(Why fix something that isn't broken!)

Agree with Elizabeth, but if it were me I would remove the top and/or bottom cover and at least do a visual. If there is anything leaking from a cap, then I would consider replacing; if all looks well, I would give the interior a gentle blast of air to remove dust and not worry about the caps for several years. Indeed, ML amps are quite durable.

Wojtek, I enjoyed my ML 20.5s for 16 years. Babied them and never had any issues with them, just great music always. Checked inside before I sold them and there was no sign of leakage of any of the caps. Last I heard from my buyer, he was still enjoying them with no problems.

Ed