Advice on 6L6 tube brands

Pens · Post by **Pens** » Sat Apr 03, 2010 7:18 pm

Okay, I need to retube my Twin I think. After a few shows where I completely cranked it, now it's breaking up at around 5 on the dial, and kind of cutting out a bit (just like how the Univox head did after a while).

So I'm shopping for sets of 4 6L6's.

It has Groove Tubes in it already. Based on what I'm seeing in my shopping:

Ruby Tubes are slightly cheaper, don't know if they are any good though, $60 for the quad
Groove Tubes are not terribly expensive, like $80 for the quad set
Sovtek tubes are $100 for the quad set, I heard they sonds cool, are they worth the expense?

Then there's JJ tubes and EH tubes, in the middle there. Are any of these any good? HALP TOO MANY CHOICES.

robroe · Post by **robroe** » Sat Apr 03, 2010 7:21 pm

sovtek

Pens · Post by **Pens** » Sat Apr 03, 2010 7:23 pm

These?

http://www.parts-express.com/pe/showdet ... er=072-314

Found this cheraper deal on a matched quad set. IS THIS A GOOD DEAL ARE THESE GOOD TUBES SHOLD I BUY NOW?!

kypdurron · Post by **kypdurron** » Sat Apr 03, 2010 7:35 pm

Those are cheap, because they are not sooo good. They work, but if you can afford better tubes, use better tubes. You will like your amp better.

Whichever you can get best, from the currently produced 6L6 tubes go for JJs, SED Svetlana (winged C) or TAD (they are the same as Svetlana) tubes. They're all good in the Twin. EHX and Sovtek is the same - and junk compared to those. Groove Tubes are relabeled Sovteks too if I'm not mistaken. So they're actually not better, but selected.

Or get some cool NOS shit if you can afford it.

I had EHX and now have JJs, that's a massive upgrade in sound (and also in reliability, the tech promised - we'll see).

Pens · Post by **Pens** » Sat Apr 03, 2010 7:38 pm

Okay, so you are saying the JJ tubes (the new Tesla brand) are better?

So these?

http://www.parts-express.com/pe/showdet ... er=072-534

FUCK! DISSENTING OPINIONS! WHY IS THIS SO DIFFICULT?!

kypdurron · Post by **kypdurron** » Sat Apr 03, 2010 7:41 pm

I would say that for a Twin Reverb, the JJ 6L6 (and also the 6V6) tubes are the best among the not-so-expensive tubes. I have these, and they are much better than EHX or Sovteks (I had those before, so I can compare

).

Though Sovteks are better than JJ if you look for preamp tubes.

Thom · Post by **Thom** » Sat Apr 03, 2010 7:56 pm

I've been looking into this recently, and I think that the conclusion I have come to is that:

If I were to re-tube my Fender amp I would either get Groove or SED Svetlana winged C's
(depending on how much cash I had at the time).
If I were to re-tube my Marshall I would get JJ's.

This is purely based of internet reading so take a with a pinch of salt, but they seem to be recommended for those amp makers more than others.

Will · Post by **Will** » Sat Apr 03, 2010 8:23 pm

I've heard nothing but good things about JJs.

Groove Tubes are ass in my experience.

kim · Post by **kim** » Sat Apr 03, 2010 8:31 pm

i don't know shit about tubes, but yes i've only heard good things about jj's and tung sol

cobascis · Post by **cobascis** » Sat Apr 03, 2010 8:38 pm

I use and reccomend JJs in my bassman

Pens · Post by **Pens** » Sat Apr 03, 2010 11:25 pm

I'm almost sold here, the thing that keeps bringing me back to these Sovtek's is the following part:

Built to rigid military standards, the 5881 will tolerate higher voltages than any other 6L6. In fact, they're frequently used as replacements for the old 7027 model in vintage Ampegs. Extremely consistent from piece to piece, The Sovtek 5881 is the most reliable current production 6L6 available

Given that I burn up tubes by cranking the fucking things so much, this sounds like a good thing to me. Is this irrelevant?

Key words here are "used in Ampegs" which is the sound I'm going for with my Twin. Loud, bright, clear. I ain't looking for bluesy bullshit breakup, I want my amp clean.

In light of this, Sovtek or JJ?

cobascis · Post by **cobascis** » Sat Apr 03, 2010 11:44 pm

Pens wrote:I'm almost sold here, the thing that keeps bringing me back to these Sovtek's is the following part:

Built to rigid military standards, the 5881 will tolerate higher voltages than any other 6L6. In fact, they're frequently used as replacements for the old 7027 model in vintage Ampegs. Extremely consistent from piece to piece, The Sovtek 5881 is the most reliable current production 6L6 available
Given that I burn up tubes by cranking the fucking things so much, this sounds like a good thing to me. Is this irrelevant?

Key words here are "used in Ampegs" which is the sound I'm going for with my Twin. Loud, bright, clear. I ain't looking for bluesy bullshit breakup, I want my amp clean.

In light of this, Sovtek or JJ?

Aren't the sovteks cheaper? If so, in combination with that info, I'd go with them.

kypdurron · Post by **kypdurron** » Sat Apr 03, 2010 11:45 pm

1st I'm not sure if this is even true, but I don't know much about data sheets for tubes. So maybe it is true. But 2nd you don't have an old Ampeg, so what they may or may not use in old Ampegs is irrelevant. 3rd, the voltage stressing the tubes is not massively influenced by the volume you play, but by the tube biasing. Oh and I wouldn't want to becitizen of a country in which the military is trusting tubes that are made like Sovtek 6L6s

I would have a bad feeling about this, because I saw how they broke. the pin socket is very fragile, and the glass is thin.

I just can't tell you anything more than I did, which is that the JJ tubes will be sounding better (clearer, more detailled over the whole frequency range) in the Twin than the Sovtek / EHX ones, and they are known to be very robust. In fact I experienced the wonder of my Twin giving me tight bass after swapping the tubes. I didn't know he could do that. So to say, on the low end of frequencies there will be a noticeable difference. Overall, your Twin will stay a Twin. No matter what you put in it.

I'm not flaming the Sovteks, they work (2,3 years) and they are cheap. But to my experience (and the statement of my tech of trust, which I can't reproduce in english, sorry

), JJs, Svetlanas and TADs are usually much better in the Twin.

Pens · Post by **Pens** » Sat Apr 03, 2010 11:48 pm

Okay, I'm convinced. Buying the JJs.

If they suck you know I'm gonna bitch at you later, right?

kypdurron · Post by **kypdurron** » Sat Apr 03, 2010 11:59 pm

maybe they'll fail and must be returned, but if they really do that burn in shit where you order they should not (after that). if they do not fail they won't suck

Pens · Post by **Pens** » Sun Apr 04, 2010 12:10 am

Ordered the quad matched set, so they should work fine. I don't think I have to get this thing rebiased since I'm replacing all four, right? This is a '65 Reissue Twin so I think those don't need to be biased?

kypdurron · Post by **kypdurron** » Sun Apr 04, 2010 12:23 am

that is your risk I'd say. Usually when you change Power Tubes in an AB-Amp like the Twin you should have its bias checked. But there is not much that can happen if you don't so it's a little bit plug and pray. If your amp runs bias rather "cold" (as Twins usually do in their stock setting) it will miss some dynamic ie will not sound as good as it could. You may not even notice that. If it runs bias too hot your tubes will age quicker and maybe fail on occasion. Before that they will sound very vivid and sexy. So you may be happy or you may not notice that too.

I'd say just put them in and if you feel something is strange (you know how your amp behaved before) let the bias check.

Haze · Post by **Haze** » Sun Apr 04, 2010 12:42 am

Hill be ordering all new JJ tubes for my Bassman soon. It had new groove tube 6L6s in it when I got it a few months ago and one of them has already started to turn a bit black. It still has the original 5881s (?) and 12ax7 that it had when it rolled off the factory lines 34 years ago. Would these be Fender branded JJs???

kypdurron · Post by **kypdurron** » Sun Apr 04, 2010 12:46 am

that would propably be american made tubes like RCA or so.

Will · Post by **Will** » Sun Apr 04, 2010 1:51 am

Haze wrote: started to turn a bit black.

That's normal with a 6L6. All tubes have a chemical coating on the inside (usually the top) that absorbs excess gas in the manufacturing process. The coating is a silvery black, turning to white if the tube fails. If the tubes are made in the GE style (as some Groove Tubes are, since they obtained the machines) this black coating is on one side and looks like a burn. Like this:

It's sometimes called a "flash mark," and it's totally normal. A black burn, as we think of it, requires a large amount of carbon. Your tube would start to deteriorate audibly before any mechanical problems.

6L6s are prone to microphonics and failure because of the size and weight of the anode plates, the operating voltage, and the number of plates inside the tube (7!).

EDIT: the original tubes would be GE, Philips, Raytheon, RCA, or any American company that contracted with the military. The one certainty is they would not be anything Soviet. Even by the 70s, the non-military market for tubes was becoming very small. They were still used by the military because tubes are insusceptible to the EM pulses from nuclear explosions.