Nov 23rd 2020 Dick Olsher Inthe past 50 years, I cant think of another power triode that has garnered a greater reverent following than the Western Electric (WE) 300B, to the point of being regarded in some audiophile circles as a virtual audio goddess. Its initial use, starting in the late 1930s, was limited to cinema amplifiers such as the single-ended WE 91A/B. The WE 300B never crossed over to mainstream hi-fi applications in the 50s and 60s due to the advent of higher-power-rated beam tetrode and pentode tubes and the proliferation of low-sensitivity loudspeakers. Then came the WE 300B renaissance. It was rediscovered in 1970s Japan, where its use was explored, mainly by hobbyists, in a variety of single-ended triode (SET) circuits in the context of horns and other high-sensitivity loudspeakers. Its fame as a linear and ultra-musical performer seemed to grow exponentially in the intervening years, as the SET wave slowly made its way from East to West. Air Tight has been committed to 300B-based SET amplification for the past 20 years. The iconic ATM-300 was released in 1999 and first made it into our Editors Choice feature in 2007. After a long pause, two more iterations of this design were released in the past five years. The ATM-300 Anniversary Edition was launched in 2016 to commemorate the companys thirtieth anniversary. And finally, with the arrival of the ATM-300R in 2018, Air Tight heralded the ultimate reference version of this design. While externally the cosmetics are unchanged, there is much to celebrate under the hood. It is Air Tights expectation that each customer will opt for his favorite 300B tube, and it ships reference units without power tubes. However, the U.S. distributor includes Electro Harmonix 300Bs as stock. Actually, its not a bad tube at all, and to be fair, let me fast-forward and reveal that it is capable of eliciting upwards of 80% of this amps sonic potential. But for those of us, yours truly included, who are addicted to the siren call of 300B sound, there are, of course, superior alternatives to consider.Read the full review here
