Best New Issue EL34

[carlg]

Rebranded EH....

I had a set of EH EL34s in my Traynor Custom Special and I thought they sounded great and I didn't have any problems the few times I gigged the amp out for bass duty. I ended up robbing them to use in another amp and ended up subbing Ruby EL34s in place of the EH. They seem to work just fine but the sound ain't what it was with the EH. YMMV....

No major problems with JJs since I've been using them as my go-to output tube some years ago.

Thanks for that, so these are the same type John was talking about then. I'm going to take his advice and skip the EH 6CA7 too. I was considering it because of the description of tighter bass. This player plays telecasters with monstrous big strings tuned down to C# so a little better bass response sounded promising but these EH tubes really don't seem to like his amp. Sounds like the JJ EL34 may be the most reliable in this group's experience?

[carlg]

Just a follow up here, I recommended the JJs to him and he decided he'd like to try something a little different this time so he ordered a quad of their 6CA7. These will NOT run at a reasonable operating point in a stock dr103. Plate voltage in this amp is 505v so at the stock bias voltage these idle at 22w per tube. I think most hiwatt owners have the voltage doubler/adjustable bias mod anyways but I thought it was worth mentioning. I biased them at 18 watts each and they sound good to me but he knows the amp better than me so I'll get his report after he's had a full band practice with them.

[wizard333]

JJ KT77s - Too "high FI" and brittle for my taste.

JJ EL34s - Acceptible on a budget. Good, not bad, but not earth shattering either.

Winged C EL34s: If you have the means, do it. Still the king of EL34 tone. Prices have become ridiculous.

JJ KT66s: Really enjoy these in my Marshall, moreso than any 34s, 6550s, or 7581s I ever had in there.

[big_teee]

JJ KT77s - Too "high FI" and brittle for my taste.

JJ EL34s - Acceptible on a budget. Good, not bad, but not earth shattering either.

Winged C EL34s: If you have the means, do it. Still the king of EL34 tone. Prices have become ridiculous.

JJ KT66s: Really enjoy these in my Marshall, moreso than any 34s, 6550s, or 7581s I ever had in there.

The JJ KT66s your running in the Marshall?
Are you running the High Impedance OT (6-8k), or a EL34 OT (3.6k) ???
Most of the New Sensor type KT66s are 6L6s in disguise.
Don't know about the JJ 66s.
B_T

[Bruce / Mission Amps]

I've switched over to JJ EL34's. So far, they seem to be the only ones that don't experience premature screen grid failure, and they sound good too. I've had problems with all of the Reflektor-made EL34's, and after getting a bad batch of 2dz. Winged-C 6L6's a couple of years back, I won't go near their stuff anymore.

Yeah man, early last year, I got scared off with a bulk purchase of the "winged C" 6L6 tubes too... almost everyone of them inexcusably failed premature.

[wizard333]

The JJ KT66s your running in the Marshall?
Are you running the High Impedance OT (6-8k), or a EL34 OT (3.6k) ???
Most of the New Sensor type KT66s are 6L6s in disguise.
Don't know about the JJ 66s.
B_T

I've never measured the primary impedance so I couldn't tell you for sure. The amp originally came with 6550s. The JJ KT66s sure don't sound like 6L6s, they have balls for days and a huge fat tone, not glassy and scooped like the usual 6L6. Far more low end authority than any other tube I've tried in that amp.

[jrfrond]

Yeah man, early last year, I got scared off with a bulk purchase of the "winged C" 6L6 tubes too... almost everyone of them inexcusably failed premature.

Yeah, all it takes is one batch like that. I had a pair literally explode out of the glass! No more. The Reflektor EL34's are a different story. The come out of the box "tired", barely reaching spec on the Maxi-Matcher. The JJ's read perfectly, and the Reflektor tubes pay you back with a greatly reduced lifespan. I can't have that when running a business. I'm buying the JJ's from New Sensor anyway, so they aren't losing my EL34 business, but until they pull it together, I'm not purchasing any Sovtek/EH EL34's.

[carlg]

An update from the Hiwatt player I set up with the JJ 6CA7 tubes. He just got in from a 53 day stretch of touring in which he played 57 separate sets. He's loving the tone and not having any more problems. That was Vancouver to Montreal and back - twice - which is a lot of bumpy miles in the van plus loading and unloading sometimes twice a day so that's a big plus one on JJ reliability over the EH tubes he had before.

[jpfamps]

My own experiences seem to mirror those of other members of this forum.

I now routinely use JJ-E34Ls for repairs as I have found recent production to be reliable (they even survive well in Laney Super Groups with HT and screen over 600V!), and I can get them at a good price, ie I my prices compare favourably with internet prices, and I still have a reasonable sales margin.

However, I stopped using JJ valves when they reduced the size of the pins as I had problems with the valves not making good contact in the sockets. When JJ increased the size of the pins I then had problems with E34Ls and 6L6s valve shorting on first application of HT and, oddly, thermal runaway, which I could only rationalize as grid emission, as the valves had been tested for gas.

I've now had no problems with JJ E34Ls (nor 6L6s) for the last couple of years.

Of the other EL34s I've tried, my favourite sounding are the =C= Svetlana, however I have some experiences of failure with these valves.

My theory is that they are very susceptible to mechanical stress; for example I had several problems with =C= valves sent in boxes where the valve can rattle around, whereas I've had no problems with =C= valves shipped in packaging where the valves can't rattle.

Having said this, I don't have a huge sample size, so this is just a theory.......

Of the other EL34s I've tried in some quantity, I not really liked sound of the EH-EL34 and had reliability issues; the S-logo Svetlanas were better, but not really available much in the UK; and the generic Chinese EL34s used by several rebranders are relative expensive and don't seem very reliable.

I tried some of the first run of JJ-KT77s and wasn't overly excited by their sound; had a rather mushy lower mid. I also had a couple short out.

[km6xz]

I do not see a lot of variety here nor that many tube amps, about 2 a week in my part time side business. But despite the low volume I see more amps come in, brand new, just from the factory(Yerasov, a popular brand here for heavy metal guys) with JJ EL34's that fail within 24 hours. The only good tubes I have available, if I beg, are the authentic Svetlana since they are located across town from me. They seem to hold up when I can get them. They have a very bad production reliability....meaning they usually have none to sell and one has to wait untill they get around to making another production run. More often than not, they have none in stock and do not get the idea that if they made some they would sell. Glass tubes are not their business however, their metal glass and metal ceramic tubes of HIGH power are their focus. A single 4cx20,000 makes a lot more profit than a hundred el34s even at their crazy high wholesale price.
I won't buy New Sensor tubes out of principle so I have been left with searching inChina for good supplies. I have a good contact in Engineering at SHUGUANG and they have been very cooperative in modifying production runs of small quantities to my spec. After a couple tweaks I am getting a EL34 I am happy with and survives in the Detonator amps., and are cheap. They are about $6 each and so far they are holding up really well, much better than the JJ and EH that have a bad track record here also. I wish Svetlana would get a manager in charge of the small consumer tube section who would beef up production and set realistic prices, but that product line is probably too much of a pain to deal with. The company has 17 divisions and the only one that is not high tech is the vacuum tubes so it does not get much attention from upper management. I've used some of their metal ceramic tubes in new designs and in RF applications and they are quite good, some of the best in the world if you need 5-50kilowatt anode dissipation tubes. But for the price of the mod'd SHUGUANG tubes and performance I am stocking up. Chinese companies are pulling ahead in high power, high vacuum devices however, lots of original research. They must have 50 manufacturers who make 1megavolt or larger vacuum switches or power tubes, versus 4 in the rest of the world.

[jmaf]

Why do you not buy from Sovtek out of principle? What happened?

[big_teee]

Why do you not buy from Sovtek out of principle? What happened?

He actually said New Sensor, which is Sovtek and many others.
I sure would be lost without my Tung-Sol 12AX7 New Production Tubes.
And, Many other New Sensor Tubes.
So Like jmaf What Principle?
They have all wound up in either Russia or China.
Terry

[jmaf]

He actually said New Sensor, which is Sovtek and many others.
I sure would be lost without my Tung-Sol 12AX7 New Production Tubes.
And, Many other New Sensor Tubes.
So Like jmaf What Principle?
They have all wound up in either Russia or China.
Terry

Yeah, I usually say sovtek to mean the whole business - I meant new sensor. Slovakia's JJ is an exception and I heard Groove Tubes made EL34's in California a few years ago, probably making it the only civilian tube made in the USA recently...I may be wrong, I don't keep up with the tube industry gossip.

[big_teee]

I had my 2204 I built this early Summer Sounding Great!
I turned it on today and before I ever Played 1 Chord I heard a Loud Pop, then Nothing.
I turned it off and checked the fuses and the .5 Amp B+ Fuse looked Like It Exploded inside the Glass.
I plugged up my Dim Bulb test unit, put in another fuse.
Everything looked good until I flipped it off standby.
The bulb gott real bright.
I turned it off and unplugged my Fave JJ KT77s, turned it back on and all was fine.
I plugged one tube at a time in and one was apparently shorted.
So I had a set of spare EL34EHs I put in and all was fine again.
So my Question and dilemma, is these KT77 tubes were only a couple months old.
I don't perform, The tubes had never been away from My house.
No rough treatment, and I bias everything low, I had them running about 30-35 ma, at 485V.
So Is this what everyone was saying to expect with EL34 Type Tubes.
I know tubes don't last forever but Damn!
B_T

[jmaf]

I've had good luck with the JJ's and contrary to this case you had, I've had issues with EH. I guess it happens with all brands, but nothing negative to report about JJ so far.