The Reference 6J5 Thread (L63, 6C5, 12J5, 6P5, etc.)

[LobalWarming]

I swear I’m being serious and know I may get torched for this question but…….for those that are burn-in believers, what do you think happens to the tube over the burn in time of 5, 50, 100 hours?

Not any mystical ‘magic’ BS but what actually happens in this process?

Not trolling, just wondering……

Burn-in? Get torched? Didn't know this was such a hot topic.

In the case of a new tube or an old tube, decades in storage, I'm willing to accept the getter could be soaking up remaining gas. Technically this should happen in seconds, however, audiophile seconds can be filled with hours of angst.

Unless one is using cold cathode tubes for audio, there's some time required for the cathode heat up its electron supply and get ready for the special electron cloud to polka like it's hot. But again, doesn't take 50 to 500 hours.

But, ime, what can change in 50 hours is my mood, perceptions and faulty auditory memory.

 

[mordy]

I’ve experienced this as well with a handful of tubes. It reminds me of those who resolder the pins in an effort to fix a noisy tube. Seems like letting it “burn-in” may yield the same result (in some cases) just take longer. Which also points to some of the components needing time to reach optimal conditions

IMHO I don’t think that the need to resolder pins is connected to burn-in. This is a condition that occurs as the solder deteriorates and undergoes certain detrimental changes as the tubes age. In my personal experience it may happen with old Sylvania and Melz tubes but other brands can also be involved.
When you try to use such a tube there are explosive pops and loud noises that unfortunately could damage drivers.
Sometimes I have had luck reheating the tube pins for 30 seconds and restoring the tube.

 

[mordy]

Yeah, I’ve been lucky and have only had perhaps 2 tubes go belly up in 20+ years.

Ironically @robo24, one was a Siemens C3G ‘S’!!!

I also had a C3gS go bad on me, but I attribute that to the fragile tempered glass in the tube.
Most tubes are removed by pulling and rocking them back and forth (rolling) but if you do that to a C3g the glass could crack.
With these tubes the best way to remove them is to carefully pry with a small flatblade screwdriver around the perimeter and gently lift up the tube from the socket.

 

[Isaacc7]

I also had a C3gS go bad on me, but I attribute that to the fragile tempered glass in the tube.
Most tubes are removed by pulling and rocking them back and forth (rolling) but if you do that to a C3g the glass could crack.
With these tubes the best way to remove them is to carefully pry with a small flatblade screwdriver around the perimeter and gently lift up the tube from the socket.

I use the 20v c3m and have been warned that the heater wire is very thin and therefore fragile especially when they are hot. No quick rolling with that one. I let them cool for 20 minutes or so. Don’t think it’s nearly as big a deal with lower voltage heaters.

 

[shwnwllms]

Speaking of broken tubes and resoldering pins, is this fixable? I hope so. I’ve never had a broken pin before and I’ve only got to listen to these Brinar 6C5G’s about 3 times.

(Full disclosure, I’m not handy with a soldering iron nor do I own one)

 

[WildPhydeaux]

That bent pin is disappointing but generally not catastrophic. Understand that the pin only extends slightly into the plastic base, it doesn't enter the tube envelop so there's no real danger of it causing the tube to vent. Therefore this is just a mechanical issue. Needle nose pliers in one hand and a firm grip around the base with your other hand an carefully bend the pin back into place, a little at a time. Do not overdo it, going past where its meant to be and have to go back since they are hollow and can crack.

Cheers,
Robert

 

[shwnwllms]

That bent pin is disappointing but generally not catastrophic. Understand that the pin only extends slightly into the plastic base, it doesn't enter the tube envelop so there's no real danger of it causing the tube to vent. Therefore this is just a mechanical issue. Needle nose pliers in one hand and a firm grip around the base with your other hand an carefully bend the pin back into place, a little at a time. Do not overdo it, going past where its meant to be and have to go back since they are hollow and can crack.

Cheers,
Robert

It’s not bent. It’s loose. I can wiggle it in any direction with my finger

 

[g0ldl10n]

Speaking of broken tubes and resoldering pins, is this fixable? I hope so. I’ve never had a broken pin before and I’ve only got to listen to these Brinar 6C5G’s about 3 times.

(Full disclosure, I’m not handy with a soldering iron nor do I own one)

Well, I would first check to see if that pin still has continuity with pin 2, as that is pin 7, and pin 2 and 7 will be your heater pins. Then if there is continuity between those, check to see if it has continuity with any other pins (which it should NOT) .. if it doesn't, then it may be as simple as using some sort of solution to sure up the pin so it doesn't wiggle/move around. If you do find continuity between pin 7 and any pin other than 2, you definitely dont want to use it, as that indicates a short within the tube and bad things would likely happen.

 

[WildPhydeaux]

In that case either the hole in the plastic is wallowed out or the inner end of the pin (inside the base) is not peened over fully. To properly fix either means replacing the base or removing it to fix the pin itself respectively - so not ideal if you're not handy with a soldering iron.

You can likely just stabilize the pin with either epoxy or "superglue". Either one will have to be worked under the shoulder of the pin with a toothpick as much as possible. If you use superglue, seek out a gel type that is compatible with high heat.

Cheers,
Robert

 

[Designsfx]

In that case either the hole in the plastic is wallowed out or the inner end of the pin (inside the base) is not peened over fully. To properly fix either means replacing the base or removing it to fix the pin itself respectively - so not ideal if you're not handy with a soldering iron.

You can likely just stabilize the pin with either epoxy or "superglue". Either one will have to be worked under the shoulder of the pin with a toothpick as much as possible. If you use superglue, seek out a gel type that is compatible with high heat.

Cheers,
Robert

I’m in total agreement with this and had recommended the same after getting a message from @shwnwllms. Zooming in on the pic you can actually see the exposed teeth at the base of the pin. Cleaning up the base, aligning the pin and hitting it with SUPER crazy glue is probably the best bet.

 

[shwnwllms]

Good to know, thanks. Unfortunately my friends like myself are too old for such thingmajigs. I don't even use a 'smartphone'.

I worry about the unprotected glass protruding under the tube. It could break when I remove the tube from the double adapter next time. The grip in the socket is very firm so I have to use a tool to pry it loose. I guess this broke the key in the first place. There is a superglue, Permabond 920, that stands temps up to 250 degrees C. I will try to find this and also use it for a loose top contact.

Viva Tubes (and a few others) sell Guide Key repair kits.

https://www.ebay.com/itm/1521491156...OqZxo2dS_i&var=&widget_ver=artemis&media=COPY

 

[AnyDave]

Viva Tubes (and a few others) sell Guide Key repair kits.

https://www.ebay.com/itm/1521491156...OqZxo2dS_i&var=&widget_ver=artemis&media=COPY

You can actual download and 3D print versions as well. I've only seen octal, but there may be others out there.

 

[shwnwllms]

You can actual download and 3D print versions as well. I've only seen octal, but there may be others out there.

He said he didn’t have a 3D printer. Hell I don’t either but I could get access to one if needed

 

[AnyDave]

He said he didn’t have a 3D printer. Hell I don’t either but I could get access to one if needed

Ah, thanks. I missed him saying that he didn't have one.

 

[shwnwllms]

In that case either the hole in the plastic is wallowed out or the inner end of the pin (inside the base) is not peened over fully. To properly fix either means replacing the base or removing it to fix the pin itself respectively - so not ideal if you're not handy with a soldering iron.

You can likely just stabilize the pin with either epoxy or "superglue". Either one will have to be worked under the shoulder of the pin with a toothpick as much as possible. If you use superglue, seek out a gel type that is compatible with high heat.

Cheers,
Robert

I’m in total agreement with this and had recommended the same after getting a message from @shwnwllms. Zooming in on the pic you can actually see the exposed teeth at the base of the pin. Cleaning up the base, aligning the pin and hitting it with SUPER crazy glue is probably the best bet.

Thanks for the insight guys. I appreciate it.

I figured out what happened, or at least a working theory

Here is the good tube. Original engraved base

Here is the one with the broken pin. It’s newer cheaper feeling plastic. Not the original engraved base like the other Brimar. This pin likely broke awhile ago and someone repaired it with a new base and sold it as NOS

Anyway if it’s already been repaired once it’s probably not worth trying again

I’ll hold onto the good one, possibly try to match it at some point if I ever decide to invest in a tube tester (there are a few singles on eBay)