2009 Fender 65' Twin Reverb reissue problems???

[Chuck H]

I'm always happy to be surprised by what I didn't know about! It's a fun way to learn something. In my defense, I don't use that many big bottles. Most of my amps, built and owned, have been el84's. And I often learn something new when I work with tubes I have less experience with.

[The Dude]

On a few occasions I've seen this problem, you can actually see the unsoldered wire inside the pin of the tube if you look at the bottom. Rare, but it does happen.

[Justin Thomas]

All of my limited experience, and I've done this exactly once... on a new-production tube, though. I think it was a 6L6... far more often I see loose bases, but the tube will still have vacuum. See that in old and new tubes.

All of this said, twinmaster should still get a new set of tubes to keep on hand! Or at least a pair... And preamp tubes, too.

Justin

[Gingertube]

I had a matched quad of JJ EL34 about 10 years back with 2 or the 4 needing resoldering on heater pins to get them to light up.
Just lucky I guess.
Cheers,
Ian

[sgelectric]

Is there a risk of losing the vacuum in the tube when resoldering octal pins?

SG

[Chuck H]

Well, I haven't done it, but...

Nope. Watch a *outube video where tubes are being made and you'll get it.

[J M Fahey]

Is there a risk of losing the vacuum in the tube when resoldering octal pins?

SG

No.

[Enzo]

Look at how a 12AX7 is made. A 6L6 is made the same way, but larger. The wire leads are longer too. They then slip a plastic base with hollow pins over those wire leads. The solder the wires inside the pins, and trim off the extra length of wire.

[Shadrock2]

I own a '65 Twin Custom 15 Reissue which has been my main gigging amp for several years. It quit in the middle of a song (like no sound at all) at a gig a few years ago. When I took it home and started looking for something wrong I noticed that one of the tubes did not light up. After pulling tubes and checking voltages I could find nothing wrong or out of the ordinary. I eventually tested the continuity of the heater pins on the dark 6L6 and found the heater continuity to be intermittent!! The tubes were the GT 6L6b just like OP. These are really Sovtek 5881 WXT's. I have never seen a failed heater connection before or since in my limited experience. I still have those tubes and it is of interest to find that it might be possible to re-solder the pins. I had not thought that possible.

I also don't have an explanation for why the amp would just up and quit like that with just a tube heater failure.

I had a matched quad of Phillips 7581 St's on hand that I installed in place of original tubes and have used the amp with those for dozens of gigs since with out a hitch.

[gui_tarzan]

Look at how a 12AX7 is made. A 6L6 is made the same way, but larger. The wire leads are longer too. They then slip a plastic base with hollow pins over those wire leads. The solder the wires inside the pins, and trim off the extra length of wire.

If you build bias checker sockets it's the same principle. I made and used one when I first got serious about repairs.

[Enzo]

Sure, that is how I made my first octal plugs, just took the base off an old 6SN7 or something, and sweated the wires out of the pins.

[TomCarlos]

Friends.... Since this thread address tube sockets (for the Fender and 6L6), I may need to replace one or two in my 65' Twin Reissue. It feels as if the pins might be a tad loose and I don't see how you can retension something like this. With the tube inserted, it seems like I can gently tugs on the 470 Ohm resistors and it has some (loose) play in it.

So just in case, is there a particular socket you'd recommend or would a basic socket like this one work ok?

BTW.... I have another thread I may need to reopen - t44403 - Before I do, I will go back through the thread and check to see if anything has changed.

Thanks!

[Enzo]

You retension these the same as the round pin kind, really.

First, is it really loose? The pins float in the holes, they are not rigidly held. So while the amp is running, wiggle that 470 ohm resistor. Does it make noises or crackles? Does it make any sign of losing contact? What matters in a socket is whether or not reliable contact is made and maintained.

In the conventional round pin socket, we take a pointed object and shove it down between the pin and the hole wall. This pushes the pin into a tighter circle. In this split pin type, we get a point down into the little slot and shove the pin prong towards the center.

[TomCarlos]

Thanks Enzo.... I will clean the sockets once again and do the wiggle test on all four 6l6 tubes.

[Familyortiz]

twinmaster,
So, in short, your exercise of subbing in a good known tube, pre or power, is a simple thing one can do to immediately look for the obvious. Nothing mysterious here at all.
I just repaired a Blues Jr that exhibited noise like a bad cable, that would come and go with banging on the cab or tapping the chassis, particularly tapping near the power tubes. Along the same lines of looking for the obvious, I inspected the board which had the power tube sockets and with the help of a magnifier, saw that one of the heater pins had a degraded solder joint. Reflowed it and problem solved. I'm just trying to hammer home the single biggest thing I've learned in 38 years of troubleshooting, which is, first, look for the obvious!