Here's a good one.. Ruby Tube quality fail.

[Randall]

A Peavey 6505 music store warranty repair came in today. Complaint was feedback and howling in overdrive channel with gain past 5 and no input. Shop owner I subcontract for had already gone a couple of rounds with it, but could not reproduce the problem. He had eliminated the pre tubes by swapping all of them already. The original Ruby's were back in it. I took a close look at the 4 6L6 outputs, also Ruby's, and immediately found the issue. Two of the outputs, both on the same side, were not glued to their bases and could be easily twisted, causing the internals to also move. This made both tubes very microphonic, but since the amp was bench tested, and not sitting on top of a cab where it would most certainly create a feedback loop, the previous tech didn't see the problem. I replaced both faulty tubes, (carefully prying them out with a flat blade as I did not think they would survive being rocked around by the glass) biased it up, and sent it out.

Also, one of the loose tube's internals had a Tower of Pisa thing going on. I understand Ruby is a Peavey product these days. Made in China perhaps? Wherever, whatever. Seeing quality control issues that bad firsthand on a new amp, I for one will be avoiding any Ruby branded products and will be advising my customers the same. Such crap these days.

[big_teee]

We have to be careful culling tube suppliers, We will run out of tubes!
I have given up on JJs, Had several issues with both JJ preamp and power tubes.
I was going to give Ruby a try, but now maybe Not!

[mhuss]

Sadly, it's become a question of who sucks least this month.

--mark

[Enzo]

Wow, condemn a complete product line from one experience?

If Peavey bought Ruby I was unaware of it. But it could be. Peavey uses whatever brands of tubes they can get reliable supply of production quantities from.

PV uses Ruby quit a lot, so far I haven;t seen a bunch of tube related warranty failures.

Ruby is a marketer, and brands tubes from various makers. Some are Chinese, and some are not. it is not a secret. The letters after 6L6 tell where they are from.

6L6GCCZ are JJs - CZ for Czech Republic

6L6GCEH are EH tubes from Russia

6L6WXT and WXT+ are Russian Sovteks

6L6GCMSTR are Chinese from Shaugang


I have been using the 6L6GCMSTR for some years no, and find them a sturdy, reliable tube. They work well in the Peavey amps.

I find tubes with the base glue cracked free now and then. It has been the case for decades. 40-50 years ago, we saw it then. Finding two in the same amp, leads me to wonder what sort of abuse the amp had suffered. Dropped? Bounced over train tracks in the trunk of a car?


If you are not comfortable using the Ruby, well, I won't try to change your mind, but my experience with the company does not fit what you describe.

[Leo_Gnardo]

Fender bought Groove Tube & that's a fact. Not a fact = Ruby owned by Peavey. In fact I don't recall having seen a Peavey that had Rubys installed as OEM parts. Sovtek, EH, in Peaveys yes all day long.

I've been buying from Ruby for @ 30 years now. Sometimes I get a clanger but most of the time they've been good, regardless of their ultimate source. And Ruby's 5AR4-C the best around unless you have a time machine and can go back in time to buy a couple crates of bungle boys or Mullards or Telefunkens.

[Tom Phillips]

...were not glued to their bases and could be easily twisted, causing the internals to also move...

That's strange. The construction of the tube and base is such that the internals are fastened to the inside of the feed-through wires at the bottom of the glass. You could take the base completely off and the tube will still operate if you connect the wires to the circuit. If the guts move independently from the glass when you twist the tube then the glass to metal seal would have been broken and the tube completely dead.

[Randall]

OK. All fair responses. BUT. The insides do move with wiggling the glass, and they are not dead. My Peavey factory authorized repair friend tells me his Ruby tubes come from Peavey. So I don't know how fine to cut that line. Two tubes with no evidence of damage other than not appearing to be glued is enough for me to be spooked. Anyhow, someone explain to me how a couple of tubes can be rocked out of their bases and still work, and how that could be shipping damage? I'mnot ready to buy that just yet.

[olddawg]

Maybe just not enough glue on that particular day and then someone twisting on them earlier. I've sen tubes break loose from the base from people muscling them. Especially vintage tubes in tight tube sockets.

[Randall]

Nope. This is a new amp, never been touched. The paper labels on the bases indicate the clamps were in the original positions. Convince me shipping could do this, because I am not buying

[Enzo]

Amp is in the box, in the back of a semi truck, on its way across the country to the store. truck is going 55 down the road. Truck hits train tracks or a pot hole or some other bump. You know how high that box can bounce? A foot easily. What goes up must come down, and it comes down hard. I can't tell you that is positively what happened, but I get stuff damaged in shipment all the time. Damage is damage, even to a tube. You found the tubes worked, even though they were free to wiggle on their leads. It isn't all or nothing, I have no trouble at all thinking the glue cracked free on a tube or two. You still have the tubes? Pull the bases off them and see if there is glue residue inside the base.

Ever open up an amp head and find the transformers are tilted a bit to one side? That is because the amp was dropped on its end. Once in a while we find a transformer snapped right off its mounting, hanging by its wires. This stuff happens. Sometimes the amp comes through it fine, other times things break.

The guy got his Ruby tubes from Peavey? Sometimes so do I. They sell them at reasonable prices, and my service center/dealer price is attractive. So when I order jacks or pots, I sometimes order some tubes as well. That way I don't have to pay shipping again to order from somewhere else. I also buy Switchcraft jacks from Peavey, and some capacitors and power resistors. Point being, the fact they also sell the tubes they use is not evidence they own the company.

[Tom Phillips]

...Anyhow, someone explain to me how a couple of tubes can be rocked out of their bases and still work...

The tube leads pass through the glass envelope via a glass-to-metal seal. That forms the working part of the tube complete with vacuum. Before the base is installed a 6L6 looks like a large 12AX7 with wires protruding from the base rather than short stiff pins. The base is slipped on and glued to the glass with the wires passed through the pins attached to the base and then the wires are soldered to those pins. If the base gets loose it doesn't necessarily damage the working part of the tube. It can be fixed by adding glue. Very useful when you need to fix vintage tube. (Or any tube that is otherwise OK)

[Ted]

Which brings me to another question. What glue do people here use in this situation?

I tend to used cyanoacrylate because it flows well into the gap between tube and old glue. I've never been entirely convinced its the best thing for the job.

[eschertron]

Which brings me to another question. What glue do people here use in this situation?

I tend to used cyanoacrylate because it flows well into the gap between tube and old glue. I've never been entirely convinced its the best thing for the job.

When I was building model airplanes, I'd get CA glue in an assortment of viscosities, all between the thin (original formula) and the all-but-useless gel stuff available now. There was always a grade that was right for the job, and using the glue that flowed correctly almost completely eliminated the mess. If you use it often enough that it doesn't cure in the bottle between applications, it should be cost-effective compared to epoxy. If you find an appropriate viscosity, there can be less mess than epoxy, too.

[drewl]

I've seen every type of tube go bad, they are fragile and it just happens.
What type of glue would work best for fixing a loose base?
I prefer to use something non flammable since its exposed to heat.

[Tom Phillips]

...I tend to used cyanoacrylate because it flows well into the gap between tube and old glue...

That's what I do and it has worked fine for me. I also use it to reattach broken center key pins when the broken off pieces are available.
Cheers,
Tom