What Do You Hear When Your Tubes Start to Run Out of Leg.
- Thread starter Tango
- Start date
This is an easy one to answer....a significant increase in noise. That noise can take quite a few different forms, but it will always be noticeable. I don't think the type of equipment has anything to do with this...noise is what you are going to hear.
OTOH, there is always that quick flash and then instant death....but that's not really what your question was about.
Many years ago, when I had an Audio Research D115/MkII amp with 6550's; the end was signaled not by an increase in noise, but with a sudden, terror inducing explosive retort and smoke, and then an expensive trip to a local shop. It was enough to instill fear and loathing in my heart about tube amps. I did later enjoy great service and sound from a pair of Wolcott Presence p200 mono blocks which simply notified the user via a blinking LED of a misbehaving EL34 at the end of the auto biasing process at turn on. You could simply replace the worn out tube. No need for matched pairs! I suspect most modern tube amps don't explode at end stage, but nonetheless, I have moved onto SS with Pass Labs and couldn't be happier.
Dear DaveyF,
May I ask what kind of noise. The noise that comes from the speakers. Or the noise generated at equipment?
Thank you for your advice.
Tang
In my experiences with signal tubes (12AX7/12AU7), the end of the good sound from tubes is when they sound 'bad'. Thin, shrill, lean, totally 'un-musical'. And for me it was not a slow death like a decrease of air and you start gasping. It happened suddenly, and sometimes at first you don't notice the bad sound till another familiar recording makes you wonder why is the sound so bad, lack of warm up, dirty lines, etc. I then had the tube tested and it was in the red zone. And those tubes were in for about 4 years with good playing time each day. Fortunately, I did not have that kind of fireworks when I had the ARC D-115 long ago. I check the biasing every now and then with my present tube amp.
I've heard some odd noises from signal tubes out of the speakers. Not super-loud but some kind of whirring/buzzing that varies in frequency.
The most frequent issue I've experienced and worst is a rectifier tube arcing over, they tend to do this when first turned on... I've had a NOS Sylvania arc over and a couple new production 5AR4s. I only run a NOS rectifier tube now.
I've also had a few new Russian tubes including Gold Lion KT77 lose their getter after using them for a short time then trying other tubes, this just happened in fact after taking the GLs out to try the Sophias. This has happened with 3 pair of new production Russian tubes now. The GLs sound great but it seems any new tube is a gamble as far as reliability.
The most frequent issue I've experienced and worst is a rectifier tube arcing over, they tend to do this when first turned on... I've had a NOS Sylvania arc over and a couple new production 5AR4s. I only run a NOS rectifier tube now.
I've also had a few new Russian tubes including Gold Lion KT77 lose their getter after using them for a short time then trying other tubes, this just happened in fact after taking the GLs out to try the Sophias. This has happened with 3 pair of new production Russian tubes now. The GLs sound great but it seems any new tube is a gamble as far as reliability.
I think it was a post from the Doc that made a lot of sense to me... Often the diminishing sound as tubes age is so gradual that the only way to really be certain is that if you suspect that the time is near, put in a new set. If you hear a difference leave the new ones in. If not, then put the old ones back and continue listening.
That is my experience as well. Right before death however there's this hashy noise. It hasn't happened often to me though. Just once in fact with a dud china peanut. So far so good with the good stuff. Sometimes I think they will outlive me.
Tang, my experience has been that you will hear the noise through your speakers. Popping sounds and other nasties are typical (major increase in tube hiss is also common). Again, as noted above, the overall sound quality will also diminish.
As i said before, we are not talking about a sudden and catastrophic failure. Instead, a sign of worn out driver or power tube.
That’s a scary circumstance that you described. Luckily, for all of the years that I owned the D70mk2 that didn’t happen to me. However, I did own a Melos tube amp in the past that did something like that...this with new Chinese KT88’s in place. Big Bang and smoke....not an exciting event at all, except for my blood pressure!
I think the problem with the D115mk2’s were that they were a little hard on the 6550’s. Particularly if you ran the amp with the tube cage in place....way too much heat was generated, leading to a likely failure. I noticed this issue with my D70mk2, so never ran it with the tube cage in place. Major heat build up is not your friend when it comes to electronics, IMO.
Thank you Phil, DaveC, Iamrae, DaveyF and Jack.
I am hearing some kind of distortion that annoy me these last few days. I played with different arms, tts and they all not up to the sound I used to enjoy. I was playing with the same phono. This phono I have about 3,000 hours on. I suspect it is the phono.
Kindest regards,
Tang
I am hearing some kind of distortion that annoy me these last few days. I played with different arms, tts and they all not up to the sound I used to enjoy. I was playing with the same phono. This phono I have about 3,000 hours on. I suspect it is the phono.
Kindest regards,
Tang
I now recall my ARC SP 14 'eats' up tubes quickly. Like less than a year, the single 6DJ8 will sound thin, lean and shrill. I was able to verify it by simply putting in a new replacement and the sound is great again. For the Jadis JPL the 3 pcs 12AX7s seem to last a lot longer, many years, while the lone 12AU7 only a couple of years. And I accidentally touched the 12AU7 one time after shutting down the preamp and the tube was very very hot. I wonder if this has an effect on the life of the tube. The Minimax preamp and phono stage both run the tubes just warm, not hot at all. One once did I ever encounter a tube that created noise through the speakers, and it was bought as used from a friend who must have bought it used and so forth it went till it got to me.
Maybe the problem is I turn on my system 7:30 am and shut down at 4:00 pm every working day and I haven’t changed any tubes.
Kind regards,
Tang
Tango, tube deterioration can be a very slow process and sometimes not that noticeable...until that is when you replace with fresh/quality new ones.
Running the gear like you do, I would highly recommend that you look into replacing all of your tubes more frequently.
Am i to presume that your gear has all of the stock tubes in it? If so, look into tube rolling, you will most likely get a nice uptick in SQ. Be careful, it can be very addictive though, LOL.
Am i to presume that your gear has all of the stock tubes in it? If so, look into tube rolling, you will most likely get a nice uptick in SQ. Be careful, it can be very addictive though, LOL.
Dear DaveyF,
Thank you for all advices. I just asked my tube guy to give me new sets of tubes.
I keep playing with my front ends so my time is all consumed by that. Rolling tube at the same time will be too much for me. I did roll my amp rectifiers once with KR but I didnt put much time on them to really let them shine.
Kind regards,
Tang
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