An amplifier built with tubes ; some types of output tubes / valves such as EL34, 6550, 845 etc can be used . Most common designs are push-pull and single ended and OTL. Those amplifiers are alternative to SS (solid state) amplifiers where no tubes / valves available. Some hybrid type of amplifiers also available.
As an audiophile upgrade is in my blood and my tube amplifier needs rolling new tubes.
by TheRambler123 September 23, 2017