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Post by Buzz Fretwear (Ignatius) on Dec 10, 2007 7:09:42 GMT -7
I've read that on this board before. Are there *any* differences???
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Post by iggs on Dec 10, 2007 7:33:42 GMT -7
That's a pretty general statement/question ...
What tubes?
Same in what regard?
JJ Electronics is a manufacturer of tubes, all tubes labeled as JJ come from the same factory in Slovak Republic.
Groove Tubes only manufacturers one of their 6L6 tubes (not sure which ones), ALL other tubes come from other factories in Russia and China ... GT tests those tubes to their own set of specs and re-labels them as GT.
Case in point ... GT KT66C ... Chinese tube made in Shuguang factory, matched, tested and relebeled by GT. If you buy the Chinese KT66 anywhere else, with any other label on it (including Penta, Valve Art ... etc) it's the SAME tube from the SAME factory.
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Post by Buzz Fretwear (Ignatius) on Dec 10, 2007 7:36:39 GMT -7
Good point - I should have specified that I think I've read the GT EL84S is actually a relabeled JJ. Is that the case? Are there any differences beyond the label?
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Post by iggs on Dec 10, 2007 8:42:57 GMT -7
Probably the same tube ... the "R" version is Russian so I assume "S" stands for Slovakia where the JJ factory is, and the only tube factory in Slovakia for that matter.
Unless it's "S" for Serbia and the tube is from the Ei factory ... I don't think so though.
Myles would know for sure.
As far as difference ... I don't know ... GT tubes are tested thoroughly, which is not an indication of quality but at least weeds out the bad ones. However, I'm pretty sure all those tubes are already checked at the factory so draw your own conclusion.
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Post by Buzz Fretwear (Ignatius) on Dec 10, 2007 8:53:13 GMT -7
Thanks Iggs, I appreciate your comments.
You know, I guess what I'm trying to conclude is this. If they're really the same tube, and if someone were to order JJ's from someone like Mike at KCA who has a great reputation for providing a quality product and he knows how to match properly - then why would anyone spend the extra $$$ for the GT's? I suppose this is a rhetorical question as much as anything.
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Post by hdahs143 on Dec 10, 2007 9:26:04 GMT -7
Yes the JJ is the GTEL84S. GT matches their power tubes at full operating voltages as opposed to static matching. What this means is that they match them at idle and at full throttle. I'm not sure how Mike @ KCA matches his tubes, but he knows what he's doing, and puts out a quality product. GT also warranties their tubes a bit longer than most, 90 days for power tubes, and 180 days for preamp tubes.
Hope this helps.
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Post by bustertheboy on Dec 12, 2007 13:11:33 GMT -7
I'm not so sure about this. When I got my Ghia it came with the GT EL84s and at the same time I got some JJ EL84's for my son's Boogie Rocket. Out of interest I swapped them in and out. The JJ's were very honky in the midrange compared to the GT's. There may have been other factors, such as hdahs matching at full throttle. Brett
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Post by iggs on Dec 12, 2007 13:34:59 GMT -7
I'm not so sure about this. When I got my Ghia it came with the GT EL84s and at the same time I got some JJ EL84's for my son's Boogie Rocket. Out of interest I swapped them in and out. The JJ's were very honky in the midrange compared to the GT's. There may have been other factors, such as hdahs matching at full throttle. Brett Well, Ghia is cathode biased ("self biased") but different tubes will have different plate current draw which will inevitably affect the sound even though the amp may reach the point of equilibrium to accommodate for the difference in tubes. Doesn't make ones better then the other in any way other then subjective tone judgment.
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Post by lowwatt on Dec 15, 2007 0:30:18 GMT -7
Yep. The EL-84S is a relabelled JJ. As has been said, with Groove tubes, you are paying extra for the level of screening, matching, and the warranty. Considering that I only buy a set of 2 EL84s every year, I don't mind paying the extra for those perks. Well worth it in terms of piece of mind and keeping my tone consistently where I like it.
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Post by myles on Jan 2, 2008 12:39:30 GMT -7
The EL84S is the JJ EL84 tube.
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Post by Phil (aka Phil) on Jan 3, 2008 5:58:23 GMT -7
Are there any vendors (Eurotubes maybe?) where you can get a JJ EL84 in a current range near what would be the GT #6? Otherwise you could get any "hardness" tube when ordering JJ's.....
Phil
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Post by amakitalo on Jan 3, 2008 9:31:26 GMT -7
If you call Bob at Eurotubes and explain what you're looking for, he'll get you there. Good service and good prices.
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Post by Buzz Fretwear (Ignatius) on Jan 3, 2008 15:05:07 GMT -7
I got mine from Mike at KCA.
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Post by myles on Jan 4, 2008 9:29:54 GMT -7
Are there any vendors (Eurotubes maybe?) where you can get a JJ EL84 in a current range near what would be the GT #6? Otherwise you could get any "hardness" tube when ordering JJ's..... Phil Tell Bob you want a tube that has "44-50" on the EL84 scale on the tester he uses. That will be in the ballpark and work pretty nicely.
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Post by Michael Bartee on Jan 4, 2008 11:54:04 GMT -7
I just play it safe and use the GT's. Great service when you need it.
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Post by Phil (aka Phil) on Jan 4, 2008 12:56:22 GMT -7
Are there any vendors (Eurotubes maybe?) where you can get a JJ EL84 in a current range near what would be the GT #6? Otherwise you could get any "hardness" tube when ordering JJ's..... Phil Tell Bob you want a tube that has "44-50" on the EL84 scale on the tester he uses. That will be in the ballpark and work pretty nicely. Thanks again Myles!!!!! I don't know what we'd do without you. Phil
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Post by heynewguy (Ol’ Bill) on Jan 5, 2008 5:44:23 GMT -7
Tell Bob you want a tube that has "44-50" on the EL84 scale on the tester he uses. That will be in the ballpark and work pretty nicely. Thanks again Myles!!!!! I don't know what we'd do without you. Phil We would be up the creek with out the paddle.
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Post by guitarboy02451 on Jan 5, 2008 18:05:59 GMT -7
You can say that again, Heynewguy... Besides, we should get the GT's and support Myles after all the hard work he does matching and slaving over those tubes day in and day out.
I think my Z's are ready for some new tubes... couple of years is pretty good out of el84's huh? Myles, do you think it's necessary to change out the pre-amp section of my SR/NR the same time I'm retubing the power seciton?
I'd like to keep it stock, JJ's in V1/2and LPS in V3.
Also, does any one know where I can buy all 3 brands at the same place? Right now it looks like the GT's will have to be a separate order the The GC or MF.
pg
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Post by myles on Jan 6, 2008 20:19:20 GMT -7
Tell Bob you want a tube that has "44-50" on the EL84 scale on the tester he uses. That will be in the ballpark and work pretty nicely. Thanks again Myles!!!!! I don't know what we'd do without you. Phil Phil ... When I am in here I try to keep my GT hat off unless somebody asks a specific GT question or if somebody has a warranty issue. I am a firm believer in trying to give players more than one option and a lot of us work hard for our dollars so if there is more than one thing that works I try to offer a few options. Sometimes the head of GT is not exactly thrilled with my independant nature but we seem to be able to work it out most of the time I love the GT #5 and #6 when it comes to the EL84 as it is not tested by the simple current output method but tested as to where the tube reaches a certain level of distortion. This makes it easier for me to replicate the tone and feel of an amp where the player was happy before. You can take two tubes with the same static output at a given static voltage and have them differ a bit so the GT distortion rating thing works in my case for a lot of things but there are great tubes out there that used more common methods that are just as cool in their own way. If you get a set of JJ EL84S in a middle current number most folks will be so close that they would love what they got and if it costs less that is icing on the cake
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Post by myles on Jan 6, 2008 20:22:47 GMT -7
That's a pretty general statement/question ... What tubes? Same in what regard? JJ Electronics is a manufacturer of tubes, all tubes labeled as JJ come from the same factory in Slovak Republic. Groove Tubes only manufacturers one of their 6L6 tubes (not sure which ones), ALL other tubes come from other factories in Russia and China ... GT tests those tubes to their own set of specs and re-labels them as GT. Case in point ... GT KT66C ... Chinese tube made in Shuguang factory, matched, tested and relebeled by GT. If you buy the Chinese KT66 anywhere else, with any other label on it (including Penta, Valve Art ... etc) it's the SAME tube from the SAME factory. Actually ... the tubes that are GT only are: 12AX7M 5751M 6L6GE 6L6CHP Black Plate 5881C short bottle EL34M (the only dual getter xf2 copy) 6CA7GE E34LS (from the JJ plant but different plates with heat sinks when compared to the JJ E34L KT88SV
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Post by myles on Jan 6, 2008 20:25:17 GMT -7
You can say that again, Heynewguy... Besides, we should get the GT's and support Myles after all the hard work he does matching and slaving over those tubes day in and day out. I think my Z's are ready for some new tubes... couple of years is pretty good out of el84's huh? Myles, do you think it's necessary to change out the pre-amp section of my SR/NR the same time I'm retubing the power seciton? I'd like to keep it stock, JJ's in V1/2and LPS in V3. Also, does any one know where I can buy all 3 brands at the same place? Right now it looks like the GT's will have to be a separate order the The GC or MF. pg I would bet you could get all 3 from Mike at KCA for one stop shopping. www.kcanostubes.comAnother source might be Doug Preston at www.dougstubes.com
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Post by iggs on Jan 6, 2008 21:04:50 GMT -7
That's a pretty general statement/question ... What tubes? Same in what regard? JJ Electronics is a manufacturer of tubes, all tubes labeled as JJ come from the same factory in Slovak Republic. Groove Tubes only manufacturers one of their 6L6 tubes (not sure which ones), ALL other tubes come from other factories in Russia and China ... GT tests those tubes to their own set of specs and re-labels them as GT. Case in point ... GT KT66C ... Chinese tube made in Shuguang factory, matched, tested and relebeled by GT. If you buy the Chinese KT66 anywhere else, with any other label on it (including Penta, Valve Art ... etc) it's the SAME tube from the SAME factory. Actually ... the tubes that are GT only are: 12AX7M 5751M 6L6GE 6L6CHP Black Plate 5881C short bottle EL34M (the only dual getter xf2 copy) 6CA7GE E34LS (from the JJ plant but different plates with heat sinks when compared to the JJ E34L KT88SV I stand corrected, I did not know that GT manufactures any other tubes and has tooling for all those different tubes at their plant.
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Post by myles on Jan 9, 2008 9:37:01 GMT -7
Actually ... the tubes that are GT only are: 12AX7M 5751M 6L6GE 6L6CHP Black Plate 5881C short bottle EL34M (the only dual getter xf2 copy) 6CA7GE E34LS (from the JJ plant but different plates with heat sinks when compared to the JJ E34L KT88SV I stand corrected, I did not know that GT manufactures any other tubes and has tooling for all those different tubes at their plant. At 2008 NAMM the GT exclusive tubes will be shown and noted along with the others.
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Post by jzguitar on Jan 15, 2008 21:53:40 GMT -7
Hey Myles
Hope you're doing well! Any info on that 5751 that I see on that GT list? I've been using 5751's in my Mazerati for a couple of years now (mostly JAN GE).
Take care,
John
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Post by jzguitar on Jan 16, 2008 19:44:30 GMT -7
Are there any vendors (Eurotubes maybe?) where you can get a JJ EL84 in a current range near what would be the GT #6? Otherwise you could get any "hardness" tube when ordering JJ's..... Phil Tell Bob you want a tube that has "44-50" on the EL84 scale on the tester he uses. That will be in the ballpark and work pretty nicely. Hey Myles I wound up ordering some JJ's from Eurotubes with those specs - they sent me this note when they shipped: "we set you up with an EL84 quad in a grade #42, but please be advised this is an extremely hot grade. Per your request, this was the hottest grade we had in stock and we very rarely see any even exceeding #38 to #40, so watch the plates on this set very closely for the first several minutes of playing time." Does this sound ok? Thanks! jz
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Post by myles on Jan 23, 2008 15:02:17 GMT -7
Hey Myles Hope you're doing well! Any info on that 5751 that I see on that GT list? I've been using 5751's in my Mazerati for a couple of years now (mostly JAN GE). Take care, John John, I am not a fan of the GT 5751 at the moment. Wait until it goes through another re-tool. For now ... get NOS ones from Mike at www.kcanostubes.com That is what I do.
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Post by myles on Jan 23, 2008 15:11:20 GMT -7
Are there any vendors (Eurotubes maybe?) where you can get a JJ EL84 in a current range near what would be the GT #6? Otherwise you could get any "hardness" tube when ordering JJ's..... Phil Phil, This is a hard sort of deal to equate as GT uses a dynamic system rather than a static system BUT .... there is hope! If you go to www.tubesandmore.com which is Antique Electric Supply and tell them you want an EL84S JJ set that measures 40-42 on THEIR test equipment it will be perfecto. I have been working with Steve over at CE Distribution for a while (they are the wholesale side of AES) and I have sent them a bunch of data that was supposed to be passed on from CE to the AES side of the house. If you run into any issues just ask to talk to Steve at CE. It does not hurt when you find a matched duet is $18.40 from them vs $40.00 from GT. When folks in here order online direct from GT if they put something in the comment section of the GT order about being from the Z Forum I hand trace the tubes that are sent to them at no cost. Tracing a duet would normally add $10 per tube due to the labor time but I still do this for the Z Forum folks. But .... for a great matched set at a nice price AES is the way to go and they worked with me a long time so I could help them with a system that is complex yet precise. Their typical match is within <= 1mA spread.
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Post by myles on Jan 23, 2008 15:15:08 GMT -7
Tell Bob you want a tube that has "44-50" on the EL84 scale on the tester he uses. That will be in the ballpark and work pretty nicely. Hey Myles I wound up ordering some JJ's from Eurotubes with those specs - they sent me this note when they shipped: "we set you up with an EL84 quad in a grade #42, but please be advised this is an extremely hot grade. Per your request, this was the hottest grade we had in stock and we very rarely see any even exceeding #38 to #40, so watch the plates on this set very closely for the first several minutes of playing time." Does this sound ok? Thanks! jz I am not sure what his numbers are but a spec EL84 at 250B+ and -7.3 bias should read 48mA as per spec. I think his machine tests at 325B+ and a -12 bias so if he is talking milliamps then this would not be a hot tube to me at all. If Bob is still using a maxi-matcher then 42 is right in the middle of the range on that unit.
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Post by myles on Jan 23, 2008 15:18:55 GMT -7
You can say that again, Heynewguy... Besides, we should get the GT's and support Myles after all the hard work he does matching and slaving over those tubes day in and day out. I think my Z's are ready for some new tubes... couple of years is pretty good out of el84's huh? Myles, do you think it's necessary to change out the pre-amp section of my SR/NR the same time I'm retubing the power seciton? I'd like to keep it stock, JJ's in V1/2and LPS in V3. Also, does any one know where I can buy all 3 brands at the same place? Right now it looks like the GT's will have to be a separate order the The GC or MF. pg You do not need to change the preamp tubes if all is working well. They will last decades. The phase inverter can be changed every few output tube changes in EL84 amps. I hard driven master volume 6L6 amps I change the PI with each output tube change. 6L6s are harder to drive and last 10 times longer in most amps than EL84 tubes. As far as where to get things in one stop shopping for less.... www.tubesandmore.com is a good option.
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Post by Deleted on Apr 5, 2008 9:32:59 GMT -7
I have a question about the ratings on EL-84's. I have a set of JJ's that have 21/4.5 on the box. These two numbers are far enough away from the 40-42 rating mentioned above that I have no idea what they mean! Can anyone shed a little light on what that 21/4.5 means?
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