What are the symptoms of tube(s) going bad?

[polkatese]

As tube aged, and slowly dying, what would be the symptoms or traits? This is specifically on the output stage of a CDP, if it matters.

TIA

[F1nut]

Static, pops and/or distortion are signs a tube is going bad.

[polkatese]

and it is intermittent too? there were days that it didn't show this, but today it did the static, and signal corruption that last half-a-second randomly at an odd interval. Doing a power cycle through the CDP seems to cure that at times.

Thank you Jesse.

[heiney9]

flat sounding, a little lower output. But as Jesse said.......snap, crackle, pop, hissing which gets louder and softer. Red glow rather than orange glow inside the envelope. What brand tube? Many current production Chinese and Russian tubes have a significantly shorter life span than NOS from the 50's-70's.

[SCompRacer]

I've had dirty pins/tube sockets cause problems like that too.

[polkatese]

It's a Russian Sovtek 6H30pi. Can't say anything about the glow since it is completely enclosed inside. So far the only issue is the one I described in #3.

[polkatese]

Interesting Rich. I've never removed it from its socket since 2004. I already ordered one from Dedicated Audio. I am really hoping this is the culprit, since it would be a major bummer if it's something else. Love this baby and it's been trouble-free since I bought it.

[heiney9]

Yes, clean the PINS sometimes that helps. 2004? You may be due for a new tube.

[SCompRacer]

It's worth a try. I've had it happen with Gold plated pins too. I have these great Sylvania Gold Brand 5687's with Gold plated pins I loved in my CD player. Every now and then I'd have to wiggle the tubes in the sockets to get the static to stop, or to get a channel to play. I found some Sylvania Gold Brand with steel pins and now life is gooder.:cool:

EDIT: Just a disclaimer, touching a hot tube with bare fingers can sizzle the skin.:eek:

[F1nut]

and it is intermittent too? there were days that it didn't show this, but today it did the static, and signal corruption that last half-a-second randomly at an odd interval.


It can be.


Doing a power cycle through the CDP seems to cure that at times.


You mean turning it off and on again?


I already ordered one from Dedicated Audio.

Is there just the one?




Just a disclaimer, touching a hot tube with bare fingers can sizzle the skin.

LOL, I would have thought you would know not to touch a tube, hot or cold, with your bare fingers.

[SCompRacer]

LOL, I would have thought you would know not to touch a tube, hot or cold, with your bare fingers.

Just don't want anyone hurt is all....;)

We of the RAS (Rockford Audio Society) do use gloves to change tubes. I'm not sure if the other guys wiggle theirs or not, gloved or bare handed.:D

[F1nut]

I'm not sure if the other guys wiggle theirs or not, gloved or bare handed.

Hehe....:D

[george daniel]

Also,, if the tube is in a pre amp circuit, you might experience a loss of volume.I've been playing with a tubed phono preamp,and had just rolled some Sovtek 12ax7lps in her,,about 3 days later I noticed a loss of volume in the right channel,,sure enough,after changing tubes the Sovetek was the culprit,,when I get my tube testor back from an unamed polkie I'll test it,,I'm sure one of the sections has gone bad.Also,,take heed in what the others have said--CLEAN PINS--sorry for the long winded explanation--I feel better now--Have a nice day.:)

[TNRabbit]

...I'm not sure if the other guys wiggle theirs or not, gloved or bare handed.:D


Hehe....:D


My first thought, Jesse~ :D



You KNOW for sure a tube is bad when it goes up in a magnificent flaming pyre, leaving a pile of molten silica....

[dorokusai]

You haven't lived until you've seen a tube blow up within itself, like a supernova.

[hearingimpared]

Just don't want anyone hurt is all....;)

We of the RAS (Rockford Audio Society) do use gloves to change tubes. I'm not sure if the other guys wiggle theirs or not, gloved or bare handed.:D

Those are some really great gloves Rich. Where can I get a pair?

To the OP when I owned the VTL 5.5 pre (for a short time) I had a tube go south. When I tapped the case or the platform is was setting on I could hear the tapping coming through the speakers. Turned out it was a tube going microphonic. I rolled in a full set of JAN NOS tubes and the problem was resolved.

[polkatese]

You mean turning it off and on again?
Is there just the one?


Jesse, yes on both counts.

[jhw59]

I've had dirty pins/tube sockets cause problems like that too.

what does one use to clean sockets, etc?

[dorokusai]

www.caig.com

I've used the SWPP (http://store.caig.com/s.nl/sc.2/category.152/.f) with great results on tube sockets. Or just wiggle it around a little and let the clamps break the contact point up.

[polkatese]

Yes, clean the PINS sometimes that helps. 2004? You may be due for a new tube.

so the question is: how long a tube with moderate use supposed to last?

[heiney9]

so the question is: how long a tube with moderate use supposed to last?

That is the million dollar question and it varies. I can say from what I've read NOS tubes tend to last longer on average. Some of my favorite tubes (Telefunken, Valvo) are rated at 10,000 hours but routinely get 15,000 hours in the pre-amp position.

Most Chinese and new issue Russian tubes are lucky to get 3000-5000 hours. But I'm just quoting averages based on what I've read. There are many that get beyond that.

Power tubes are a completely different beast as far as longevity but in general older tubes last a bit longer.

H9

[hearingimpared]

That is the million dollar question and it varies. I can say from what I've read NOS tubes tend to last longer on average. Some of my favorite tubes (Telefunken, Valvo) are rated at 10,000 hours but routinely get 15,000 hours in the pre-amp position.

Most Chinese and new issue Russian tubes are lucky to get 3000-5000 hours. But I'm just quoting averages based on what I've read. There are many that get beyond that.

Power tubes are a completely different beast as far as longevity but in general older tubes last a bit longer.

H9

According to Musical Fidelity and Jesse, the tubes in my Tri-Vista preamp stage are rated at 100,000 hours. Something to do with the use of tubes from the Russian MIGs.:rolleyes::rolleyes::rolleyes::eek:

[dorokusai]

I think the data from Musical Fidelity, the manufacturer, would suffice.

[F1nut]

Actually Joe, the tubes were originally used in the guidance systems for US missiles, something Musical Fidelity, the manufacturer won't tell you. They are also rated for an altitude of 60,000 feet.

[hearingimpared]

I was actually joking about the MIGs but there you go, they were used in some kind of aeronautics.

What I wasn't joking about was the 100,000 hours, I believe this IS what they are rated. Even if it is drummed up a bit it's still impressive and you are correct they are nice tubes.

[george daniel]

Colossus

http://en.wikipedia.org/wiki/Colossus_computer

and the Foxbat

http://www.globalaircraft.org/planes/mig-25_foxbat.pl

I had some NOS tubes that I bought from a Russian Gent,, came in a plastic tray with lid,, had the "Red Rocket" logo on the boxes,,kinda cool actually,, sold em to a third world country to help start their one plane airforce.;)

[hearingimpared]

That's some cool reading George.

[george daniel]

thanks--what got me going was the fact that the Russians relied heavily on tubes,because they would still operate in certain "nuclear" conditions when other electronics would not,, as in communication and guidi ence systems,,the fact the some manufacturers use a tube that is soldered/secured in place-speaks volumes.

[hearingimpared]

thanks--what got me going was the fact that the Russians relied heavily on tubes,because they would still operate in certain "nuclear" conditions when other electronics would not,, as in communication and guidi ence systems,,the fact the some manufacturers use a tube that is soldered/secured in place-speaks volumes.

Yep, the tubes in my preamp stage are soldered in and from what I understand from Jesse, they are a bear to replace. I have the replacements but I hope I never have to do so.

[polkatese]

Soldered? wow, that's hardcore!

so, those jets with tubes, do you think they care if the tube turned microphonics? can they tell just by listening to the engine rev? :p

I am waiting for the replacement to arrive, I am hoping THAT's the problem. It is frustrating when it only happens intermittently.

[heiney9]

Polkatese, I bet that's your issue. Have you cleaned the pins and lightly wiggled it around in the socket just to be sure?

[polkatese]

Not yet. I did vacuumed the inside of the enclosures about a month ago. Might try your suggestion this weekend. Thanks Heiney.

[jhw59]

www.caig.com

I've used the SWPP (http://store.caig.com/s.nl/sc.2/category.152/.f) with great results on tube sockets. Or just wiggle it around a little and let the clamps break the contact point up.

thanks!

[SCompRacer]

My gear uses a 5687 military tube.

A 5687 variant, the 6900, was used in ICBM warheads. It is a very robust tube with ceramic spacers. It has twice the transconductance of a 5687. It is rated for a 500G impact shock load and 50G vibrational acceleration. The 6900 was originally manufactured by the infamous Bendix Redbank Division. MU Engineering bought the Redbank Division, rebranded existing stock and continued to manufacture tubes on Bendix tooling. I've not heard a difference between either brand. I sold off the more expensive Bendix and kept the MU's.

http://i417.photobucket.com/albums/pp260/scompracer/Tubes/mu6900.jpg

[polkatese]

That's one cool tube Rich!

[polkatese]

Guys, Let's say that after I wiggled the tube, it plays fine again, does replacing it with a newer tube makes it sound better? think of it like replacing the bulb/lamp of a RPTV, which would make it looks like brand new again. Does tube degraded over time like a RPTV bulb? sorry if it sounds like a rather obscure question..

[hearingimpared]

Guys, Let's say that after I wiggled the tube, it plays fine again, does replacing it with a newer tube makes it sound better? think of it like replacing the bulb/lamp of a RPTV, which would make it looks like brand new again. Does tube degraded over time like a RPTV bulb? sorry if it sounds like a rather obscure question..

That could definitely mean that the tube pins were grimey or loose in the mounts, however, when a tube is going south they usually go intermitent first then just degrade over time. Unless of course you get a power tube that just goes "super nova" like the one Doro described.

[polkatese]

thanks Joe. I pray to God that none of my gears ever go supernova on me, no matter how cool that is, and how's that made Mark went into ecstatic mode. :)

[hearingimpared]

thanks Joe. I pray to God that none of my gears ever go supernova on me, no matter how cool that is, and how's that made Mark went into ecstatic mode. :)

I witnessed a go partial super nova at an audio show at Quest for Sound. He had an awesome Raysonic integrated tube amp that had those power tubes with the second anode type connector on the top go kablooey while we were listening to some Pink Floyd and it was kind of cool looking. Kind of like enclosed fireworks. BTW those tubes were huge and shaped like the old long necked light bulbs and hotter than hell.

[polkatese]

So, I took the tube out and cleaned the pins. Put it back and right now checking it out. So far so good, haven't heard the problem.

As it turned out, the tube is 6H30pi-EB variant. I googled it and it is supposed to be higher reliability and long lasting tube (-EB). I have ordered the regular Sovtek. Anyone familiar with it? The most expensive is the -DR variant ($150+), but from what I read, all of them are sort of the same. I was looking at the -EH variant (Electro Harmonics) with gold pins. It is about $10 more, but supposedly it has better bass, and mid, but less dynamic. I don't need anymore bass as is, pretty happy with its presentation.

Heiney, looking at the tube, it looks fine other than the slight discoloration (brownish) ring which I supposed due to heat. It has Herbie tube damper on it. I wonder now whether I should even mess around replacing it since this one is well burn-in over 6 years, but glad that at least I have a spare tube if need be.

[hearingimpared]

So, I took the tube out and cleaned the pins. Put it back and right now checking it out. So far so good, haven't heard the problem.

As it turned out, the tube is 6H30pi-EB variant. I googled it and it is supposed to be higher reliability and long lasting tube (-EB). I have ordered the regular Sovtek. Anyone familiar with it? The most expensive is the -DR variant ($150+), but from what I read, all of them are sort of the same. I was looking at the -EH variant (Electro Harmonics) with gold pins. It is about $10 more, but supposedly it has better bass, and mid, but less dynamic. I don't need anymore bass as is, pretty happy with its presentation.

Heiney, looking at the tube, it looks fine other than the slight discoloration (brownish) ring which I supposed due to heat. It has Herbie tube damper on it. I wonder now whether I should even mess around replacing it since this one is well burn-in over 6 years, but glad that at least I have a spare tube if need be.

My CDP came stock with EHs. I was given EH goldpins and it sounded better and I can't say that liked either but it wasn't until I rolled in some Jan NOS tubes that Beardog sent me that the CDP sounded just right to me.

[polkatese]

Thanks Joe. Tube rolling in this puppy is a pain due to where it mounts, so I was thinking about EH but not sure if I have the drive.

So I've been spinning for over an hour, and hasn't hear any anomaly. Perhaps wiggling and cleaning the tube worked?

DSOTM in Multichannel is awesome! (forgot how awesome it was, I guess)

[polkatese]

Got the replacement this afternoon. Btw, I've had dealt with www.dedicatedaudio.com a couple times and found them to be very fast shipping, and excellent service by the owner, Daniel Hammond.

The replacement turned out to be an -EB variant. I am happy. Now that the problem hasn't surfaced since I wiggled it, I am prepared.

Thanks everyone!

[hearingimpared]

Got the replacement this afternoon. Btw, I've had dealt with www.dedicatedaudio.com a couple times and found them to be very fast shipping, and excellent service by the owner, Daniel Hammond.

The replacement turned out to be an -EB variant. I am happy. Now that the problem hasn't surfaced since I wiggled it, I am prepared.

Thanks everyone!

Good stuff!!!

[doctorcilantro]

Hum = heater to cathode leakage (break-down of the ceramic slurry over time which electrically isolates the heater from the cathode, or just a badly made tube with HC leakage).

Hum = poor production > bad structural integrity/misaligned plate structure (or due to mishandling)

Hiss, pops, and static = gas levels beyond what the the getter is capable of sequestering after long term use

Hiss, pops, and static = improperly seated in the socket; contaminated pins

Distortion or loss of gain = low emission etc.

Directly heated power triodes can make some noise upon power up too....

[samnor]

Somewhat of a thread jack but I am wondering along similar lines as to whats the signs of a solid state amp going bad other than the same symptoms (static, buzzing, etc)... I'm trying to pick up a used amp and I would atleast like to know a good heads-up as to when I should stop using the amp before I fry my speakers..

[doctorcilantro]

Somewhat of a thread jack but I am wondering along similar lines as to whats the signs of a solid state amp going bad other than the same symptoms (static, buzzing, etc)... I'm trying to pick up a used amp and I would atleast like to know a good heads-up as to when I should stop using the amp before I fry my speakers..

Easy.....FIRE.

[reeltrouble1]

C is for Cookie
C is for Cookie
C is for Cookie

I have a Magnavox Radio from the 50's with original tubes that still works just fine. I tell you this because it makes me way cooler.

Glad the issue seems resolved I have been using that 6h30 tube for a while and it seems to last around five years for my playing habits.

SS amps make great boat anchors when they buzz, the buzz also stops after one anchor use.

RT1--oh yea, I almost forgot, I have a young lady friend who comes over, she plays guitar with me, she also is willingly to lean over and change my tubes, very dainty flexable thing she does......Tubes Rule.

[hearingimpared]

C is for Cookie
C is for Cookie
C is for Cookie

I have a Magnavox Radio from the 50's with original tubes that still works just fine. I tell you this because it makes me way cooler.

Glad the issue seems resolved I have been using that 6h30 tube for a while and it seems to last around five years for my playing habits.

SS amps make great boat anchors when they buzz, the buzz also stops after one anchor use.

RT1--oh yea, I almost forgot, I have a young lady friend who comes over, she plays guitar with me, she also is willingly to lean over and change my tubes, very dainty flexable thing she does......Tubes Rule.

Well this is the second thread in 5 minutes that I've read that has me wetting myself laughing!

[polkatese]

Thanks Doc!

I replaced the tube anyway, since it has been 5+ years and a newer one won't hurt Ted.


RT1--oh yea, I almost forgot, I have a young lady friend who comes over, she plays guitar with me, she also is willingly to lean over and change my tubes, very dainty flexable thing she does......Tubes Rule.

He he. YOUR tube RULE!