Dave Gordon on KT 150s:
"Quoted specs for the amps have not changed. Although we could change some of the operating voltages and get higher rated power output," says Dave Gordon of Audio Research, "we are going the conservative route, which we think will provide greater reliability and tube life. We expect owners to get 3000 hours out of these tubes, about 50% longer than KT120-equipped amps."
Quote from my Ref 160M manual which is also available on line at the ARC website:
"A Note about Vacuum Tubes Life Expectancy The vacuum tubes in your Reference 160M have been burned in, tested and electrically matched to provide the best performance and reliability of your amplifier. That said, vacuum tubes must be replaced from time to time. The KT150 output tubes in the Reference 160M should have an expected life of approximately 3,000 hours, while the smaller 6H30 tubes should have a life expectancy of approximately 4,000 hours. These life expectancies are only approximate."
I’m surprised that the ARC website now contains a general statement about tube hours which does not distinguish between KT120s and KT150s as the website used to do. I think this was an inadvertent failure.
"Quoted specs for the amps have not changed. Although we could change some of the operating voltages and get higher rated power output," says Dave Gordon of Audio Research, "we are going the conservative route, which we think will provide greater reliability and tube life. We expect owners to get 3000 hours out of these tubes, about 50% longer than KT120-equipped amps."
Quote from my Ref 160M manual which is also available on line at the ARC website:
"A Note about Vacuum Tubes Life Expectancy The vacuum tubes in your Reference 160M have been burned in, tested and electrically matched to provide the best performance and reliability of your amplifier. That said, vacuum tubes must be replaced from time to time. The KT150 output tubes in the Reference 160M should have an expected life of approximately 3,000 hours, while the smaller 6H30 tubes should have a life expectancy of approximately 4,000 hours. These life expectancies are only approximate."
I’m surprised that the ARC website now contains a general statement about tube hours which does not distinguish between KT120s and KT150s as the website used to do. I think this was an inadvertent failure.