Who makes the highest quality tube amps?

Aries Cerat is the new innovator in tube design with brand new technology introduced to tube amplification never been done before across the entire lineup

Impera II Preamp - Inverted Triode technology
Pondera Preamp - Negative Output Impedance Energey(Power) Supply (NOIES)
Diana Forte - Highest Powered Stereo SET amp in the world
Ianus - Brand new TriodeFET Hybrid design
Collatio - First True Class A SE OTL Amplifier
Etc

http://aries-cerat.eu/
 

nobody mentioned mastersound, unison research, viva

Collatio - First True Class A SE OTL Amplifier

This is most certainly false. Single ended OTLs have been around for decades and by definition are class A.

All tube OTL amplifiers use SEPP, cyclotron or Mr. Futterman’s variations. All these are push-pull amplification stages. They can claim single ended, but they are push pull topologies. Feedback is mandatory in this designs to cancel out the artifacts generated by the problems of not true complimentary driving of the signal, and of course cross-over distortion. Some clever variations have been presented on the market during recent years, but they are nevertheless push pull topologies with many dbs of negative feedback, some of them use up to 60db of degenerative feedback. Of course, these amplifiers are not Class A devices.

Manley Labs and conrad johnson.