I am currently just past the recommended 2000 tube life on my power amp. (Audio Research Ref 110). It still sounds glorious. Am I playing with fire here? Or, will I notice some degradation in sound that will prompt the re-tube. I think it's about $1,000 to retube.
Without knowing how they measure, you have to (literally) play it by ear. If they sound good, then enjoy them. Obviously, you will need to re-tube at some point, so you might consider purchasing a new set of tubes now if it's in your budget. If you're really curious, put the new ones in for a few days/weeks to see if you notice an increase in performance. If you do, keep 'em in. If you don't, put the old ones back in and get more mileage out of them.
However, you say your amp sounds "glorious." In that case - I wouldn't change a thing!!
2000 hrs use recommendation is conservative by audio research
you can extend a good 20-25% past that if you are careful don’t listen loud or have had to drive speakers
the problem with arc amps of your ref110’s lineage is that there is no tube failure protection, so a failing power tube can (and often does) take out a bias resistor and maybe scorch a little section of the pcb, needing a minor repair
given the size and heft of the amp, even a minor repair becomes a pain for handle and ship
so most play it safe, replace tubes sooner than later, follow their recommendation
you can always monitor how close to being used up your tubes are by how much the bias current needs to be turned up from when they were new, i track that...
One of the best mechanics I ever knew growing up back in the day, a real experienced old guy, said if it ain't broke don't fix it. No wait, that's the cliche. What he said was, everything you do costs time and money and entails some kind of risk. No wait that's not right. Tell you the truth, don't remember exactly what he said. But whatever it was if it ain't broke don't fix it will do.
if you do swap in a fresh set of power tubes to hear them, BE SURE to turn down the bias current substantially BEFORE installing the fresh tubes, then, over 30-60 min playing music, gradually increase the bias to get to the 65 ma reading across the test resistor for each side holding steady... if your present set of well used tubes are properly biased now, that bias setting will be WAY TOO HIGH for the new set
detailed instructions on biasing (using a simple multi meter with hook probes) are in your manual
you don’t want to fry your new set or age them prematurely by doing this swap incorrectly
I can tell you that catastrophic tube failure can be quite expensive. It cost me $650 and the builder was generous with me because it was not that old. But I bought it used and thus no warranty. I also learned the pitfalls of buying an amp that has not been broken in yet. Break in can happen either for the good or it really BREAKS in, IE failure. BTW It had protection too. But, it still took out a power supply.
FWIW if you have a catastrophic failure, you will need tubes AND repair. 8 tubes should not cost $1k. Driver tubes may be alright since they have about double the life of power tubes. Just a thought.
You can wait till your amp sounds lifeless, but ARC state 2000hrs, idling, with music, it does not matter. Start thinking of re tubing. Better safe than sorry.
Usually I wait until a tube gets noisy to worry about it, I've never had a power tube go bad and damage my amp. I have had rectifiers go out twice once taking out a resistor another time blowing a fuse. Probably a wise thing to do is get a retube now and use your current tubes as emergency backups as tubes can and go get noisy and the least convenient times.
As I've posted in other threads, I own a PrimaLuna integrated amp that senses when a power tube is about to fail, puts the amp in safe mode - - and tells you which power tube is the culprit. In several years of ownership that feature has kicked in twice - potentially saving me a lot of grief and money.
Questions for the group - are there any other tube amp manufacturers that offer a similar feature? If not, why not? I don't pretend to understand how the "bad tube indicator" circuit in the PrimaLuna works - - or the costs involved. But it has proven its worth to me, and I rest a bit easier knowing it actually works.
Go ahead and order a set of tubes. You're going to need them soon, so why wait? This way you'll have them on hand when the old ones start to go and you'll experience no down time. You will know when it's time to make the change, your SQ will change for the worse.
I used to have a set of Manley Neoclassic 250s. Turned it on with an old set of tubes one day and BAM! Power tube went down swinging and took out a resistor. Luckily Manley sold these clip on replacements so I was able to get them replaced myself. Always a risk with old tubes.
Was just listening to a copy of Joni Mitchells "Mingus"I picked up earlier today.
Last track on side two.
Distortion.
Thought I had a bad pressing.
Lifted the arm, played the last track again to see.
Left channel dead.
Checked to see if I had pulled a speaker wire or an interconnect - was moving gear around.
Then I noticed the lovely glow of an EL34 that was red plating.
Ugh...
Thankfully, I had a back up set of tubes ready to go if something failed.
Had a set of Winged 'C' tubes that lasted forever a bunch of years ago. These Gold Lions I've been using have a terrible failure rate, as do the Psvane EL34PH replicas that I bought a couple of years ago.
Sound wonderful! Just don't last...
Basic Tung Sol EL35B as back up.
Next set of tubes will be the Winged 'C' again.
So yeah, your tubes could fail tomorrow, or not.
If, there is a risk of a cascading effect from a failed tube, then see if there is anyone near by with a tester and check the state of your tubes.
But, a back up set is always a good idea. A little inventory can't hurt.
I would contact somebody like Upscale Audio or Brent Jesse let them know what type of system you have and the tubes you are currently using and let them recommend some NOS tubes not only will you be replacing your tubes but you will also experience a much better sound. Good luck
Another silly post with a simple obvious answer. If you can't hear any difference why change the tubes??? You gain nothing. But by all means keep a spare set waiting for the day.
Another silly post with a simple obvious answer. If you can’t hear any difference why change the tubes??? You gain nothing. But by all means keep a spare set waiting for the day.
yes this is generally sound logic with most tube amps but arc tube amps run the risk of needing a repair to bias resistors and/or the circuit board area near it, if a power tube has a ’hard fail’ - despite the wonderful sound of these amps, this is one of the issues arc amp users face, and thus, typically users replace tubes before they are close to being totally shot
I would contact somebody like Upscale Audio or Brent Jesse let them know what type of system you have and the tubes you are currently using and let them recommend some NOS tubes not only will you be replacing your tubes but you will also experience a much better sound.
nos power tubes are not a practical option with modern arc tube amps - we are talking modern day kt120 or kt150’s which the amps are tuned for driving, for maximum power and transparency
but kevin deal or jim mcshane will sell you properly screened and burned in sets of these for the ref110 upon request - there were shortages of these through last year when covid hit but as of late in 2020 supplies started catching up
nos power tubes are not a practical option with modern arc tube amps - we are talking modern day kt120 or kt150’s which the amps are tuned for driving, for maximum power and transparency
Just call Upscale Audio, a very big dealer in bottles (tubes), and buy the bottles from him. If you've ever wanted to tube roll, here is your chance to have a bit of audio fun. Next, buy a multimeter along with a small screwdriver, and bias the thing yourself.
One thing you absolutely need to keep in mind is to replace the 6550 power rectifier tube at 2000 regardless of whether you remove the 8 power tubes. If you don’t and that tube fails (you won’t hear anything in terms of sound because it’s not in the signal pathway) you can fry the board. And that is a very expensive repair......
I have a different amp , but tubes none the less . About 2 years ago I got back into vinyl , so I put a fresh set of KT-120’s into my amp. ( auto bias ). The current ones had plenty of life , but after warming up the new ones, there was a noticeable sonic improvement. I purchased them with matching and burn in . So I just let them warm up a couple hours and listen . I have some of the exotic NOS tubes like Tungsol 3 hole , GEC KT-66 and KT-88. But I love the Winged C tubes ! As far as failure , a brand new current production GL KT-77 failed and damaged my amp . Had to send it in for repairs. A capacitor blew with such force that it snapped the junction tab in two, as it’s a point to point unit . Heard a huge pop on my left speaker , but no damage . One of the Winged C’s let go and the glass fractured . The tube internals turned snow white, but no damage . Fortunately, I was standing in front of my system and turned the amp off . Ah the things we do for Harmonic Distortion! Cheers , Mike.
You will have to have the tubes tested to see how they are but tube sound degradation happens over a period of time slow loss until the tubes fail so you do not really notice until you have to fix the tubes because of noise issues or replacement because of total failure.
One thing you absolutely need to keep in mind is to replace the 6550 power rectifier tube at 2000 regardless of whether you remove the 8 power tubes. If you don’t and that tube fails (you won’t hear anything in terms of sound because it’s not in the signal pathway) you can fry the board. And that is a very expensive repair......
@co93
let’s not confuse matters, ok?
the arc ref110 does not run a 6550c as a rectifier -- it uses solid state rectification
I phoned my local shop a few weeks ago, inquiring about my old B&K pro10mc preamp (the mid 90’s version.) for a recap, new volume pot, as the stock came in a sealed pot, & there are no originals out there. He asked me if it has static, or noise, or anything else,...I said the only issue is some crosstalk via some inputs, but this is normal on this pre, and the static on the volume control. I said, I keep the pre off, and go back & forth with the vol knob, many many times, to spread some of the grease bad on the track, it s fine I said, he said, there is no need to waste money, I was shocked, She still works, as does my aging Onkyo p-308, and my elite dv-79avi player. When the pioneer goes out , I will be sad, the best player I’ve ever owned, sonically, video, etc.
the aging McCormack I bought used is no slouch!!,....the UDP-1 a nice player, only issue is we have another elite the dv-48 I think?? Using the remote with one player turns on the other, (nothing a thin piece of colored tape remedies)
Your money, your tubes, if it sounds great,.then rock on, but that (WORRY) I’m sure is in your head, sending a massive spike to a speaker,......and frying something.
I feel the same way with my amps,. You never know how, or when it *may* happen.
I did send in my Sunfire to that flannery guy, he was a pleasure to deal with, a bit more $ than I thought was charged / vs, the parts replaced, etc. but, the amp is like new, plows through any speaker I hook up, even my friends Aerial’s and my modded CV D-9’s with a 2.6-3.? Ohm dip.
Back on track, ....1K is not too bad, as far as audio goes, may be find a nice mom n pop place to do the work.
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