How can I tell if my tubes are ok?

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Samhain said:
You need a palm reader/crystal ball & someone who can predict the future to know how long a tube will last.
Sometimes 50+ years. Sometimes 2 days.
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Isn’t there a way to test the gain or some other number that shows how it tests? Doesn’t this tell you if a tube is newer or near the end?
 
Cap217 said:
Isn’t there a way to test the gain or some other number that shows how it tests? Doesn’t this tell you if a tube is newer or near the end?
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Testing the gain would entail a much more expensive machine than the one I use. If the tube tests in the very first part of the green or 'good' part of the meter range then you could assume it's almost at the end...but as I said before I've had vintage Sylvania 6L6 test that way and they are still going strong. As I stated these cheaper machines can at least tell you if the tube has any life left, which keeps you from putting a dead tube in and prevents a larger failure with the amp.
 
Problem is/ is the tube could pass every test on any tester with flying colors and still crap out.
Many here have said its best to spend 40/90 bucks on a new pair or quad and be done with it.
Not a question "if" it will die but "when".
 
Samhain said:
Problem is/ is the tube could pass every test on any tester with flying colors and still crap out.
Many here have said its best to spend 40/90 bucks on a new pair or quad and be done with it.
Not a question "if" it will die but "when".
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And like I said before, I have bought 'new' tubes only to have a few red plate immediately upon install. That's exactly the purpose of my tester..to prevent a bad tube from ever being installed in the first place.
In a perfect world new tubes all work great without problems. But clearly it's not a perfect world. If you want to trust that new tubes won't fail, your choice. They shouldn't, if they're new...but that hasn't always been the case. Every tube I've tested that shows life left, haven't failed. Not once.
For peace of mind that 50 bucks I spent long ago was well worth it.
 
Racerxrated said:
And like I said before, I have bought 'new' tubes only to have a few red plate immediately upon install. That's exactly the purpose of my tester..to prevent a bad tube from ever being installed in the first place.
In a perfect world new tubes all work great without problems. But clearly it's not a perfect world. If you want to trust that new tubes won't fail, your choice. They shouldn't, if they're new...but that hasn't always been the case. Every tube I've tested that shows life left, haven't failed. Not once.
For peace of mind that 50 bucks I spent long ago was well worth it.
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And not to mention when you buy tubes that the seller describes as NOS only to find out there’s no life left in them.
 
If you can bias with new tubes and it sounds good to you/ Play. When you buy new tubes you will see if one is bad pretty quick, unless youre buying NOS you shouldnt need a tester imo.
 
And on NOS 1/2-3/4 out there are fake, that shit is gone a good a while ago.
 
panhead said:
If you can bias with new tubes and it sounds good to you/ Play. When you buy new tubes you will see if one is bad pretty quick, unless youre buying NOS you shouldnt need a tester imo.
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Not necessarily. I had a KT 88 fire up just fine in a VHT D60....after biasing ( they were matched) I played for about 10-15 minutes and then major static/weird sounds; took a look and one red plated... Brand new tubes from The Tube Store.
 
panhead said:
And on NOS 1/2-3/4 out there are fake, that shit is gone a good a while ago.
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With the prices they've been asking for NOS stuff, I've been buying ANOS tubes for a few yrs now and stopped about a year ago since I have a large stash now. That's probably the main reason I have it; just to make sure they are good when I get them.
I recently grabbed a 2205, and fired it up without testing the tubes. Of course, one of the JJs was bad and immediately took out a grid screen resistor.
I didn't even follow my own advice and almost lost a transformer. And, I know better with JJs not to trust them. Especially used.
 
What’s already been said is why I bought tube testers. It’s worth it to me to know EXACTLY what’s in my amps.

I also use it to let people know when buying an amp from me, tubes are tested and good… so that they don’t have to buy a new set. Quite a few times I’ve bought amps I told the sellers to now ship with the power tubes as I don’t want their junk. ?
 
Racerxrated said:
Not necessarily. I had a KT 88 fire up just fine in a VHT D60....after biasing ( they were matched) I played for about 10-15 minutes and then major static/weird sounds; took a look and one red plated... Brand new tubes from The Tube Store.
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Thats what im talking about , you will know
 
panhead said:
Thats what im talking about , you will know
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Yes..but...not necessarily right away. I used to watch them as I fired the amp up for the first time....if they're gonna go bad that should be pretty fast after firing it up...but 10-15 minutes later? What if I put the guitar down for a few minutes (not on standby) to run upstairs for some reason..in that time the bad tube could decide after I walked away for a few minutes to go bad...that scenario leads to some serious repair bills.
For me I just have better peace of mind when I buy tubes or a different amp...I can just throw the tubes on the tester to be safe. If you can find a decent deal on one, I feel they are helpful enough to justify 50 bucks.
 
Eico 667 is what I use. I have a couple of them.. They work real well. The tube catalogs are rare unless you find one with the winding built into the tester which are cool. Not to expensive
 
Racerxrated said:
Ever buy tubes from a trusted retailer only to have one red plate on you? Willing to take that risk + the hassle of going after the retailer to replace your transformer? Not me. I've had 5 separate instances where tubes from The Tube Depot, Eurotubes, Dougs and a few more that I forget have each had a bad power tube that IMMEDIATELY red plated. Bad out of the box. That scenario can EASILY take out a transformer and ruin a nice valuable vintage amp. Each time the retailer immediately sent a replacement, no hassles BUT the damage could have been disastrous. Luckily I watched as they warmed up and started to red plate so I was able to turn the amp off fast.
Yes, when you buy NEW tubes they can be bad right outta the box. These simple testers help identify a bad tube BEFORE it damages your amp.
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Tubes redplate for various reasons, and I learned what they were. First off, you can get a hot pair rated, say 42, when your old pair was biased for a pair rated 26. Guess what? The bias is going to shoot way up right off the bat. If you don't know what you're doing that could be a problem. It's a good idea to lower the bias considerably before starting, and go up, vs firing it up and seeing 90mA and lowering. That alone could redplate out of the box. User error/lack of understanding.

Scenario #2, tube sockets. The retainers get stretched out, you plop in a pair that don't seat properly, and guess what? Redplate. Lesson - Tighten up your pin retainers.

Scenario #3 Some dipshit plops them in, (breaks a guide pin, and indexes it wrong), fuse blown. BAD tube!

There's 3 cases of user error. Now, I'm not suggesting this is the case with you personally, but it's sure funny how people bitch about BAD tubes, when some people don't know what the fuck they're doing. I learned the hard way about the tube sockets. Bought some JJ's from Bob at Eurotubes about 15+ years ago for a JSX. They redplated. I called and complained, (and those who know Bob will tell you), he told me I was a dumb fuck and to tighten up the retainers. The factory Ruby's had far thicker pins, and opened them up wide. The JJ's were much thinner making poor contact. He was 100% correct. I was a newb. And 20+ years of buying and retubing probably 100 amps, it's never happened again. I've had a few go bad, but no redplating out of the box. Never known them to take out a transformer either. That's what fuses are for, to prevent that.
 
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Personally, if I get an amp and it works and sounds good, I don't touch a thing. Even brand new tubes can be a crapshoot
 
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napalmdeath said:
Tubes redplate for various reasons, and I learned what they were. First off, you can get a hot pair rated, say 42, when your old pair was biased for a pair rated 26. Guess what? The bias is going to shoot way up right off the bat. If you don't know what you're doing that could be a problem. It's a good idea to lower the bias considerably before starting, and go up, vs firing it up and seeing 90mA and lowering. That alone could redplate out of the box. User error/lack of understanding.

Scenario #2, tube sockets. The retainers get stretched out, you plop in a pair that don't seat properly, and guess what? Redplate. Lesson - Tighten up your pin retainers.

Scenario #3 Some dipshit plops them in, (breaks a guide pin, and indexes it wrong), fuse blown. BAD tube!

There's 3 cases of user error. Now, I'm not suggesting this is the case with you personally, but it's sure funny how people bitch about BAD tubes, when some people don't know what the fuck they're doing. I learned the hard way about the tube sockets. Bought some JJ's from Bob at Eurotubes about 15+ years ago for a JSX. They redplated. I called and complained, (and those who know Bob will tell you), he told me I was a dumb fuck and to tighten up the retainers. The factory Ruby's had far thicker pins, and opened them up wide. The JJ's were much thinner making poor contact. He was 100% correct. I was a newb. And 20+ years of buying and retubing probably 100 amps, it's never happened again. I've had a few go bad, but no redplating out of the box. Never known them to take out a transformer either. That's what fuses are for, to prevent that.
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Scenario 1: In my case the new pair were installed and 1 redplated immediately. The other tube did not. I shut the amp off. Pulled both tubes. Put my bias tool on the tube socket and checked the tube that did not red plate-34ma. Then I checked the tube that started to red plate and the bias kept climbing and climbing…shut it down immediately. Clearly, I received a new tube that was shit.
Scenario 2: Nope. Never
Scenario 3: Nope. Never

My latest tube story took out a grid screen resistor-not a fuse. So your “that’s what fuses are for” didn’t apply. That’s now a trip to a tech, because of a shit JJ EL34L.
If I would have followed my own advice I would have discovered that bad JJ..but I was in a hurry and I wanted to hear the amp right away.
I always make sure tubes are seated properly and you can tell when retainers need tightening just by wiggling the tube as it sits; you’ll know if it needs to be tightened.
New tubes can fail. New/old tubes WHEN they fail can damage an amp.
True story.
The overwhelming majority of new tubes will be just fine.
But, it only takes one….
 
Racerxrated said:
Scenario 1: In my case the new pair were installed and 1 redplated immediately. The other tube did not. I shut the amp off. Pulled both tubes. Put my bias tool on the tube socket and checked the tube that did not red plate-34ma. Then I checked the tube that started to red plate and the bias kept climbing and climbing…shut it down immediately. Clearly, I received a new tube that was shit.
Scenario 2: Nope. Never
Scenario 3: Nope. Never

My latest tube story took out a grid screen resistor-not a fuse. So your “that’s what fuses are for” didn’t apply. That’s now a trip to a tech, because of a shit JJ EL34L.
If I would have followed my own advice I would have discovered that bad JJ..but I was in a hurry and I wanted to hear the amp right away.
I always make sure tubes are seated properly and you can tell when retainers need tightening just by wiggling the tube as it sits; you’ll know if it needs to be tightened.
New tubes can fail. New/old tubes WHEN they fail can damage an amp.
True story.
The overwhelming majority of new tubes will be just fine.
But, it only takes one….
Click to expand...
True that... There's definitely bad ones out of the box! I've been lucky, I guess. I've had more JJ ECC83S's go bad than any other, followed by Tungsol 12AX7's.

Only times I can remember having a power tube go fairly soon, were from Tube Depot. They sold some shit SED EL34's back when they started having quality issues, and eventually stopped making them. What pissed me off was they knew the quality was shit, and refused to take responsibility. The Manager there, (don't know if he's still there - probably) was a REAL asshole.
 
I’ve been into buying ANOS tubes for a few years; my tube tester can at the very least tell me if it is shot. For me it’s worth it to have. But if I had to pay a lot more for one I’d maybe pass…was only 50 bucks. In defense of the bad new tubes the dealer did send me a replacement fast.
 
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