When were the best tube amps made?

Any amp that can't even reproduce a simple sine wave doesn't count. If the negative half of a sine wave doesn't go down as far as the positive half goes up the amp is non linear and may be musical but it's not fidelity. If it does that to a sine wave think how poorly it will do on much more complex music wave forms. By the way this means every single ended amp and it's not curable since it's inherent in single ended topology.

2022. Audio Research, Conrad Johnson, VAC… unless you have different sound preferences from me.

@jasonbourne52  they all sound the same the cheaper the better. Snake oil!

IMO the older amps benefited from better transformers.  Think Dynaco.  In repairing audio components for close to 30 years now, the transformers have stood the test of time but the circuit boards have generally failed.  Each manufacturer from back in the day had build a few amplifiers that still sound great today especially with a few parts upgrades.  Just finished an old Audio Research D-79B.  Once upgraded, it really sounded great.  A beast of an amp though.  Futterman, Graaf, Lafayette, etc., were great sounding amplifiers, even some Counterpoints amps sounded great.  Unfortunately, 20 to 30 years later, they need to be repaired.

As someone else mentioned already, no real advances in tube amps but there are a few really good tube manufacturers around today that build excellent amplifiers.  My company is one of them. Hand built, point-to-point wired, best parts available that are even better sounding than the old amplifiers.  There are a few of us still making great equipment.

Happy Listening.

The best tube amps are being made today. Unfortunately, with the exception of the best current 300Bs, the best tubes aren't. But from, say, the 1950s to the current day, the pace of improvement in SS amp technology has radically outstripped tube technology.