Audio Research runs their power tubes at 50% so 3000 hours is about right. Good article in Stereophile last year about the new REF 160(kt150) amps. They discuss tube life.🎵
Life of KT150 tubes on ARC Amps
I have Audio Research 250SE amps and the tubes in it have 2400 Hours. I wanted to hear experience from other ARC users if they replaced KT150 tubes before 3000 Hours. I am not sure if i need to replace them now or wait for some more time. I dont have new set of tubes for me to compare with my current tubes and wanted to hear from other people who replaced the tubes.
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I have an ARC VT200 amp that I love(d) (with an ARC LS25 mk II preamp) - it sounds great - but the pain and expense of retubing it has become just too much for me. I just bought a pass labs X250.8 amp to replace the VT200. It's wasn't just the expense of retubing it - it's also 20 minutes it takes to warm up when wanting to listen to music - and the hassle of getting the amp to someone who can retube it for me. I once ordered the tubes myself to save money and one of the tubes arc-ed and i had to send it to get fixed anyway. I leave the pass amp on all the time and if i want to listen i just need to press PLAY on my CD player remote - I can play it whenever and not worry abt using up my tube life. The VT200 did sound great though :) Steve |
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. "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? . |
I am very happy with my 75SE, which has been upgraded to SE status for at least 3 years. I haven't replaced the tubes and have no idea how many hours they have on the clock. I listen a lot to my Stax l700 ear speakers anyway, so don't believe I am over 2000 hours. I have to say that the numerous stories of damage when a tube blows, do concern me. Are there any other clues to near failure, such as wandering bias? It would be nice to change them just before one blows. My amp only has 4 tubes, but they are still costly when you have retired. |
fsonicsmith322 posts02-01-2019 9:44am 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 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.... . |
Well, we have Iris Dement in common. Tis a shame she has put out so little music. 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. For the most part, this is a thing of the past, but it was a huge problem back in the 90's. I don't think that there is anything magical about my Ref 150SE and I have no doubt that any number of competitor tube amps including the RM-200 equal or exceed it. I do believe that the ARC Ref 6 and Ref 10 preamps are among the best five preamps currently available. My Ref 6 makes me smile every time. Huge soundstage and a magical quiet forcefulness. I am one of those who believe the preamp is the single most important piece of electronics and is the heart of any system, more so than the amp or speaker. My choice of amp simply followed my choice of preamp. They match and are compatible though any number of other tube amps would also work well. |
Oh no, I forgot to mention one thing. Last one, I promise. Brooks wasn’t an ARC dealer (he had sold the brand when he was at GNP in Pasadena in the 80’s), but he loved having customers who owned them. He sold them a lot of RAM tubes, and also made money repairing them everytime a power tube took out some parts when it blew. The shelves of his used equipment racks were full of ARC power amps, everyone of them having scorched circuit boards. The brand reminds me of not Porsche, but Fiat ;-) . |
I know man, Roger Modjeski and The Band, my two crusades. Also Bruce Thigpen and Iris Dement. I shall attempt to curb my enthusiasm out of consideration for ARC apologists, if for no other reason. Before I do though, I wonder how many have actually heard the RM-200 Mk.2 or Eminent Technology LFT-8b? Brooks Berdan enthusiastically recommended both to me, but that was on a friend-to-friend basis. To his paying customers he sold Jadis, VTL, and Wilson. WAY more money to be made selling brands with audiophile cache’ and bragging rights. Higher price = better sound? I have no doubt that lots of people dismissing the RM-200 Mk.2 (particularly in comparison to the REF 75SE/150SE) have never listened to the amp. They just "know". |
For the price of retubing a big amp directly from ARC, one can buy a used Music Reference RM-200 (100w/ch), which needs it's four output tubes (a pair of KT88 or 6550 per channel) replaced only every 10,000 hours. And like folkfreak's VTL, the MR tubes are fused, so no fireworks ;-) .So you suggest I should of bought 5 Hyundai Santa Fe instead of my Porsche 911? :-):-):-):-):-):-) bdp24, what do you do when you are not pimping for Roger? I mean really man, give it a break. It is tiresome.Don't think you want to know. |
Definitely replace well before failure. There are many horror stories of the effects of tube failure in ARC amps. One of the best things about the VTLs I own is how well they handle tube flame outs, taking down a fuse only with lots of on board diagnostics to help you problem solve the issue ive also found that pre amp tubes also need replacing well before rated life, they gradually go off and sound much more wooly, in my ARC phono and pre I found that even at 1500 hours they were markedly worse than a broken in new set |
veerapaneni OP106 posts01-30-2019 7:32pm 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 |
@ 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 |
@jea48................ just because the amps are 22K each doesn’t mean the guy is rich. For all I know, he could have taken a home equity loan on them. It is a lot of money for anyone to own those amps and have to retube them every 2000 hours. Most amps will do 3000 hours but I guess ARC drives their tubes harder than most. |
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. |
I had a pair of KT120s last around 2 years of daily listening (amp on 8 hours maybe every day I'm around) to a Jolida 502p...I recently replaced a pair of KT77s in my current Dennis Had SE amp as one of the tubes stopped working...lit up, looked fine, no sound...damn...the good news is the amp only uses 4 tubes total, and one's a rectifier...smaller amps will bind you to efficient speakers, but otherwise assuage any concerns about tube cost being a big deal...ARC's tube wear seems extreme but maybe they drive tubes harder or something...are the new Carver claims of very long (five year warranty includes tubes) tube life an actual thing? |
Average life for power tubes is 1500 to 2000 hours. From Audio research: Power Amplifierhttp://www.audioresearch.com/ContentsFiles/FAQs_April_2018_rev3.pdf . |