I have had an 333 since we purchased it new in 1995. About three years ago, it failed, and I had it repaired at an authorized facility for about $2500. I continue using it and have no plans or desire to replace it. It is very difficult today to find an alternative which could have one's confidence that it could drive any speaker you may want in the future.
In recent months, our audio club has had two videoconferences with prominent amplifier designers. I asked each, "should I replace my amplifier?" (One was John Curl, the other the head of Schitt Audio.) Each essentially replied "probably not," and that amplifier design had not changed significantly over the decades.
As far as I can discern, the 333 sounds very good.
Here is a review for the 333:
https://www.stereophile.com/content/mark-levinson-no333-power-amplifier
In recent months, our audio club has had two videoconferences with prominent amplifier designers. I asked each, "should I replace my amplifier?" (One was John Curl, the other the head of Schitt Audio.) Each essentially replied "probably not," and that amplifier design had not changed significantly over the decades.
As far as I can discern, the 333 sounds very good.
Here is a review for the 333:
https://www.stereophile.com/content/mark-levinson-no333-power-amplifier