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Modern EL34 reliability?

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  • #16
    Originally posted by nsubulysses View Post
    Why use EL34 when there is KT77 and 6CA7?
    Are you talking about NOS or modern production tubes? For new built stuff, I haven't checked for differences in the spec sheets, but I wonder if those other model names are just more marketing foolery.
    Originally posted by Enzo
    I have a sign in my shop that says, "Never think up reasons not to check something."


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    • #17
      The key with JJ tubes is to buy them from someone who adequately tests and screens the tubes prior to sale. I've gotten JJ's from AES/CE Distribution on the past and also from Eurotubes. There was a problem with AES/CE Distribution for awhile and they changed their screening of tubes prior to sale and it seems to have resolved the problems. I usually buy from Eurotubes since they are local to me and I can just go over and get them instead of having to pay for shipping. I've never had an issue with JJ tubes, but I don't use a while bunch of tubes either so YMMV.

      BTW, I've used some of the JJ KT77's and I like them. They sound good and were very reliable.

      Greg

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      • #18
        Originally posted by soundmasterg View Post
        I've used some of the JJ KT77's and I like them. They sound good and were very reliable.
        Similar story here for JJ's KT77 & 6CA7. But the crustomer complains "they sound different, not like EL34." Well they are beam power tubes, it's true, not "real" pentodes. Someday I'd like to try an experiment, scrape off the lettering, paint on 'EL34' and see if they complain then. (put devil-horn smiley thing here...)
        This isn't the future I signed up for.

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        • #19
          I think some of that "they sound different" thing is caused by the fact that the old tubes were worn out and the new ones aren't. Ears adjust to that "worn out" sound over time- just as it takes time to adjust to the "new" sound.
          I'll equate it to this. When I started as a tech, I did house calls on TV's. Much of the time picture tubes would be worn out and color balance was way off- to the point the picture would be leaning heavily to one color. I would readjust the set for a nice even picture with accurate color balance. Then, the sweet old lady sitting in her arm chair would say, "It doesn't look right. There's too much red". So, I'd put it back to the green picture I started with just for sake of making the customer happy. Hell, if watching a TV that's the rough equivalent of watching a monochrome monitor makes her happy, who am I to argue?
          "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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          • #20
            I've wondered if people that are surprised (or disappointed) by the sound of new power tubes weren't just 'ear tone' tuned to their old, crappy tubes. But I have to say... Put a set of JJ E34L's up next to a set of Ruby EL34B's and then tell me which one sounds like an EL34 should. Lot's of guys on the Marshall forums are onto the Ruby offerings too. Fortunately most Marshall amps (and therefor most amps that use EL34's) are head design. The microphony was problematic for me. YMMV. I have two pair of the Ruby's right now. The boxes are strapped together with a rubber band and "head only" is written on the boxes (by me) with a sharpie. But they sound just great and DO take some abuse.
            "Take two placebos, works twice as well." Enzo

            "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

            "If you're not interested in opinions and the experience of others, why even start a thread?
            You can't just expect consent." Helmholtz

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            • #21
              Originally posted by g1 View Post
              Are you talking about NOS or modern production tubes? For new built stuff, I haven't checked for differences in the spec sheets, but I wonder if those other model names are just more marketing foolery.
              I am talking about new stuff.

              KT77 and 6CA7 are attractive because their max plate and screen voltages are 800V/800V and 800V/500V respectively. FWIW, I believe JJ lists the 6L6GC plate and screen voltages as 500V/450V max.

              Both seem to be more robust variants of EL34

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              • #22
                Are EL34s kinda flimsy because theyr'e $12?

                I know catalin gramada has recommended to me in the past to use KT77 or KT66 in rough screen grid scenarios because for some reason it handles it better than 6CA7/EL34.

                I was too cheapskate to try KT66 and I didn't want to use KT77 because someeone I know already built an amp with that power section. So I arbitrarily didn't want to use it, although I like it. Good Idea huh?

                Also as someone mentioned earlier maybe it's about the seller. CE has done me pretty good I'd say. I always buy 24 hr burn in when possible too. I'd like to think it makes it more reliable but who knows. It just gets shipped half way across the country then anyway on a bumpy truck

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                • #23
                  I've been using Shuguang EL4B for a while now and without problems. They are rebranded by TAD and a dissection shows the electrode assembly to be identical, though there could perhaps be some material differences. Maybe. The real difference is in the envelope thickness. A Shuguang tube weights 47g, the TAD 54g. Marshall is also using Shuguang tubes as OEM.

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                  • #24
                    In The above mentioned combo I have three of those silicone rings on each tube and another snaked around each spring retainer to keep them in line. I even considered shock mounting the sockets, but found a happy place before I had to do that. I wonder if the Ruby EL34B has the heavier bottle. TAD does often order their own modifications to their tubes rather than just rebrand. At least that's what I interpret from the web.
                    "Take two placebos, works twice as well." Enzo

                    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                    "If you're not interested in opinions and the experience of others, why even start a thread?
                    You can't just expect consent." Helmholtz

                    Comment


                    • #25
                      Originally posted by Randall View Post
                      ...
                      I put a set of Rubys in a Marshall Jubilee that was running at 525v. I also then put it on a bucking transformer to bring things down a bit. AFAIK it is still running.
                      Was this biased much closer to Class B than Class A?, and what ra-a did you select?
                      Building a better world (one tube amp at a time)

                      "I have never had to invoke a formula to fight oscillation in a guitar amp."- Enzo

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                      • #26
                        Are you guys re-tensioning the output tube sockets when you install JJ's?

                        Their pins are skinnier and have caused alot of failures in stuff I get in.

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                        • #27
                          Originally posted by drewl View Post
                          Are you guys re-tensioning the output tube sockets when you install JJ's? Their pins are skinnier and have caused alot of failures in stuff I get in.
                          Skinny pin JJ octal base tubes were a major headache for too many years when JJ first came on the market BUT I haven't seen any such for over a decade. If any are still stashed somewhere and find their way into current sales, I'd return them to the seller immediately and demand my money back. Any techs still have them in stock from the early 2000's? I'd take a hammer to them, just accept the loss of trashy product. Yes they were rubbish. Thank hevvins currently made JJ's no longer have this problem and I hope it stays that way.
                          This isn't the future I signed up for.

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                          • #28
                            Seriously?
                            Every JJ tubed amp I see has has the thinner pins.
                            Thanks for the update.

                            I'm not a fan of New Sensor buying up the naming rights to great old brands, but are you guys seeing failures from their EL34's?
                            Whether they be bogus Mullard, Tung Sol or Svetlana?

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                            • #29
                              Originally posted by drewl View Post
                              Seriously?
                              ...
                              I'm not a fan of New Sensor buying up the naming rights to great old brands, but are you guys seeing failures from their EL34's?
                              Whether they be bogus Mullard, Tung Sol or Svetlana?
                              Yes, the latest 'Svetlana' EL34s I put into a Marshall RI SL100 2 days ago blew up last night. :-(
                              Building a better world (one tube amp at a time)

                              "I have never had to invoke a formula to fight oscillation in a guitar amp."- Enzo

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                              • #30
                                I have a much harder time finding good octal tube sockets that don't stretch irreparably upon first insertion than I do finding quality tubes...

                                Okay, let the sex jokes roll.

                                Justin
                                "Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
                                "Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
                                "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

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