Life of KT150 tubes on ARC Amps

Average life for power tubes is 1500 to 2000 hours.

From Audio research:

Power Amplifier

Output tubes last up to 2,000 hours.
Note: Near the end of the tubes sonic life, aging vacuum tubes may degrade the sonic character of the product(s) they are used in. Make sure to replace your tubes before outright failure occurs. We stock vacuum tubes and match sets to the specification on each model. Audio Research tubes undergo thorough testing prior to being selected for use in our equipment. To order replacement tubes please contact your local dealer or send us a message at service@audioresearch.com for pricing information.

http://www.audioresearch.com/ContentsFiles/FAQs_April_2018_rev3.pdf


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@ stereo5   

At $22,000 each I would be willing to bet a $1000 a year is pocket change.
Jim


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@ stereo5

Take at look at the OP’s 2ch system. I see $150K easy. Maybe not rich, but LOL, he sure ain’t poor.
Jim

jetter882 posts01-30-2019 7:11pm


But somehow retube costs of ARC amps is a familiar topic here.

Well thanks to gpgr4blu post, the KT150 tubes in the OP’s amps are good for up to 3000 hrs.

veerapaneni OP106 posts01-30-2019 7:32pm

I read they are good for 3000 Hours but at 2400 hours they are not sounding that great and always played at very low volumes.

From ARC Link.

Note: Near the end of the tubes sonic life, aging vacuum tubes may degrade the sonic character of the product(s) they are used in. Make sure to replace your tubes before outright failure occurs.

@ veerapaneni,

A very nice 2ch system indeed......

Cheers,  
Jim

@ veerapaneni

One thing you might want to check is the AC mains voltage at the outlet/s the amps are plugged into. The mains voltage can affect power tube life. Power tubes will last longer if the mains voltage is, say, 117Vac than if it is 123Vac. Check the mains voltage at the wall outlet/s with the amps powered on. Higher voltage increases the tube filament voltage as well as the DC power supply voltage.

Say the voltage measures 123Vac - 125Vac. You may very well be at the end of the tube life of the KT150 power tubes with 2400 hours on them.

Also worth noting, how often do you check the bias for the power tubes? Listening hours of use between checks....


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fsonicsmith322 posts02-01-2019 9:44am

It is no secret that ARC feels that fuses and other methods of circuit protection degrade the sound and also no secret that ARC’s practice of having a single resistor act as circuit protection for tube failure is a pain for the customer. If a tube fails, the resistor not only needs to be replaced but on occasion there can be more damage to the circuit.

Older ARC amps are not user friendly when it comes to biasing of the power tubes, that’s for sure.

As for the screen resistor that blows if the power tube runs away I find it hard to believe ARC didn’t know when the resistor blows, burns/blows apart, from being over loaded that ARC didn’t know the event could cause damage to a circuit trace.

It’s just common sense the resistor should not be installed close, tight, against a circuit trace on the circuit board. At the very least a fire rated insulator should have been installed between the resistor and the circuit trace to protect the trace from being damaged in the event the resistor blows, burns, explodes, apart. In fact the resistor should not be installed against the circuit board as it is. At the vary least it should be at minimum 1/8" from the board for even cooling around it. When you are pushing the amp, the tube, that resistor can/does get physically hot.


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veerapaneni OP107 posts01-30-2019 7:32pm

I read they are good for 3000 Hours but at 2400 hours they are not sounding that great and always played at very low volumes. I am doubting the 3000 hours number now and that’s why i posted this topic originally, to get other user opinions on the SE line Amps.

I read they are good for 3000 Hours but at 2400 hours they are not sounding that great and always played at very low volumes.

"at 2400 hours they are not sounding that great"........

Time to replace the tubes!


At $44000 I would want the amps to sound their best. Period. No way in hell I would go over 3000 hrs. What do you think it will cost to send one or both amps back to ARC for repair if a tube/s shorts out and causes internal damage?


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