Instead is using a mixed brand batch of NOS 6L6GC’s for my current hybrid amp project, I splashed out on a new matched quartet of 6L6EH’s. However, I think the guy/gal who assembled the one pictured below was on the vodka.
The other three aren't particularly straight either, but this one is the worst.
Has anyone here ever tried straightening one of these out? I’m guessing maybe the glue that holds the base on can loosened with a really hot heat gun????
The other three aren't particularly straight either, but this one is the worst.
Has anyone here ever tried straightening one of these out? I’m guessing maybe the glue that holds the base on can loosened with a really hot heat gun????
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The EH6L6GC and the Sovtek 6L6WXT look different from any 6L6GC that I have ever used. They seem to work pretty good, and can take some serious abuse. I have about 10 of them. At least 5 of them are not perfectly straight. Yes 5 out of 10 is poor odds, but I have some equally crooked RCA's and GE tubes, so the Russians don't have the market cornered on bent tubes.
I have also got some Russian tubes labeled "Orion" brand, obtained from a tube seller in Hong Kong. The 6L6GC's were all consistent, and of good quality. They passed my "serious abuse" tests. The EL34's were absolutely the worst constructed tubes that I have ever seen. The grid rods were all bent, and 2 of the 4 tubes arrived with internal shorts. Oddly enough, I was able to clear the shorts by whacking the tubes on the workbench. The tubes function , and don't sound half bad, but I am sure that a fireworks display will occur if I ever attempt to operate them near the max ratings.
I have also got some Russian tubes labeled "Orion" brand, obtained from a tube seller in Hong Kong. The 6L6GC's were all consistent, and of good quality. They passed my "serious abuse" tests. The EL34's were absolutely the worst constructed tubes that I have ever seen. The grid rods were all bent, and 2 of the 4 tubes arrived with internal shorts. Oddly enough, I was able to clear the shorts by whacking the tubes on the workbench. The tubes function , and don't sound half bad, but I am sure that a fireworks display will occur if I ever attempt to operate them near the max ratings.
I've bought ones that were both crooked as shown and of slightly differing heights as well. All have worked fine, and if I look hard enough through my not inconsiderable* stock of NOS tubes I can find many examples of the same thing.. 
I'd leave them completely alone as SY suggests.
* I am not nearly in the same league as George (Tubelab) when it comes to shear quantity..
I'd leave them completely alone as SY suggests.
* I am not nearly in the same league as George (Tubelab) when it comes to shear quantity..
I Get lots Of JJ's like that all the time.
I have a couple 6V6S's here that are about as bad is the one in the picture above.
I got a couple EL34's with opposing tilted bottles that really look sick in my guitar amp, More the 3/8" difference between the tops and bases.
But all things considered they work just fine and compared to NOS prices, I just use them.
I wish these companies would realize that most of us would be willing to pay a bit more for better quality, both mechanical and electronic !
They make themselves look bad sending out less than perfect junk, But they make themselves look even worse by not caring to improve!
Trout
I have a couple 6V6S's here that are about as bad is the one in the picture above.
I got a couple EL34's with opposing tilted bottles that really look sick in my guitar amp, More the 3/8" difference between the tops and bases.
But all things considered they work just fine and compared to NOS prices, I just use them.
I wish these companies would realize that most of us would be willing to pay a bit more for better quality, both mechanical and electronic !
They make themselves look bad sending out less than perfect junk, But they make themselves look even worse by not caring to improve!
Trout
Trout said:
I agree. Considering the fact that probably 90% of those who actually buy these things actually plug them in to designs in which valves are on display, one would think that physical appearance is one thing the manufacturer would pay particular attention to.
The forming of the glass in my valves is quite consistent, it’s just the plastic bases which are glued on crooked.
I don’t know exactly how these things are assembled, but I doubt that a decent assembly jig which accurately lines up the plastic base with the glass bulb would be a particularly difficulty thing to arrange, even without significantly increasing manufacturing costs.
Cheers,
Glen
Maybe they have impoved slightly over the past 5 years. I have about 10 Sovtek 300B tubes. There is over an INCH difference in bulb height between the shortest and the tallest. Unfortunately 5 of them are DEAD (don't ask me why I am saving them). They all died after the 90 day warantee expired, but before 6 months had passed. I have only recently resumed the use of New Sensor tubes.
tubelab.com said:
Well, I only have four of them to compare though - I could just have a good sample
The 300B also has a much larger and more difficult to manufacture bulb that the 6L6EH.6L6's are a lot cheaper than 300B's, but I still hope that my 6L6EH's prove to be more sturdy that your 300B's!
I'll take note to steer clear of Sovtek.
Cheers,
Glen
I have a friend who is a tube vendor. I went to visit him one day. He had a large box full of "previously auditioned" New Sensor tubes. All had TubeStore.com stickers on them, and obvious clamp marks on the bases where they had been used in guitar amps. I believe that they were returns that tested good. I could take my pick for $10 each, with a money back guarantee. I bought them all. I have torture tested many of these tubes far in excess of the ratings. The EH KT88 and 6550 (same tube) seem to be virtually indestructable, and they sound good too. The EH 6L6GC and the Sovtek 6L6WXT (again the same) are some serious 6L6 type tubes. I have tested them at dissipation levels over 30 watts. These do seem to be sturdy tubes.
Glen,
By this time you have all the info you need from really experienced guys, so I will just say that of some 20 6L6EHs I have used, most were not seriously un-straight. You really have the limit!
You would also have concluded: Definitely do not mess with the fixing; it is not going to melt and you will probly end up with something over-stressed. You would have noted that the pins through the glass bottom go directly into the base pins - the mounting of the glass is more rigid than with the older types feeding thin wires to the base pins. That is high temperature "glue" - I have measured the temperature on the glass envelope of a 6L6 at 190 degrees.
Regards
By this time you have all the info you need from really experienced guys, so I will just say that of some 20 6L6EHs I have used, most were not seriously un-straight. You really have the limit!
You would also have concluded: Definitely do not mess with the fixing; it is not going to melt and you will probly end up with something over-stressed. You would have noted that the pins through the glass bottom go directly into the base pins - the mounting of the glass is more rigid than with the older types feeding thin wires to the base pins. That is high temperature "glue" - I have measured the temperature on the glass envelope of a 6L6 at 190 degrees.
Regards
Johan Potgieter said:
G'day Johan.
I have decided that I’m not going to attempt to ‘fix’ my 6L6, but I have been wondering how the wires are attached to the pins in these modern valves.
I’ve repaired heaps of old receiving tubes for old radios/transmitters by re-gluing the plastic bases, which commonly come completely loose from the glass bulb do to deterioration of the glue after several decades of intermittent service. The connecting wires of the old valves generally allow quite a lot of movement of the plastic base.
Cheers,
Glen
Glen,
Coming back to this, the information in my post #14 was in fact in error.
I have just recently "chopped up" a defunct 6L6EH, and found that the base is not stuck to the glass with any adhesive. It is simply held in place by the internal pins protruding through the flat glass bottom, being soldered into the base (hollow) pins.
This does open some leeway, but still risky. If one can heat up all of the base pins simultaneously one might be able to pull the glass unit clear or at least shift it straight. If I were to do this, I would construct a special copper ring capable of being fitted to the end of a high power soldering iron, to hold against all the pins simultaneously. Applying a flame could damage the base, also it should be noted that a rather thin glass tube (the vacuum seal), goes rather deep down the centre stem of the base.
Up to you, if you consider it worth your while. I have just broken the centre base stem off one of my 6L6EH, and might gather the courage to try desolder and fit a new base off another tube.
By the way, this "non-glued" construction also seems to be prevalent in other similar shaped power tubes. My EL34s are similar; one can detect that by examining with a magnifying glass. But one should make quite sure!
Regards.
Coming back to this, the information in my post #14 was in fact in error.
I have just recently "chopped up" a defunct 6L6EH, and found that the base is not stuck to the glass with any adhesive. It is simply held in place by the internal pins protruding through the flat glass bottom, being soldered into the base (hollow) pins.
This does open some leeway, but still risky. If one can heat up all of the base pins simultaneously one might be able to pull the glass unit clear or at least shift it straight. If I were to do this, I would construct a special copper ring capable of being fitted to the end of a high power soldering iron, to hold against all the pins simultaneously. Applying a flame could damage the base, also it should be noted that a rather thin glass tube (the vacuum seal), goes rather deep down the centre stem of the base.
Up to you, if you consider it worth your while. I have just broken the centre base stem off one of my 6L6EH, and might gather the courage to try desolder and fit a new base off another tube.
By the way, this "non-glued" construction also seems to be prevalent in other similar shaped power tubes. My EL34s are similar; one can detect that by examining with a magnifying glass. But one should make quite sure!
Regards.
Well have a look at my row of 807's...... Check the rightmost tube:
PS I've showed this pic before.
An externally hosted image should be here but it was not working when we last tested it.
PS I've showed this pic before.
soundbrigade said:
This remionds me of the morning after the night before.
Regarding the use of adhesive in tube bases... I remember at one time seeing some brown gunk in the base of tubes, but that was many years ago when tubes were tubes and men were men. I don't remember if the brown gunk was an adhesive or filler, but personally, I would learn to love the skew little guy. Don't fix what's not broken!
-F_D
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