The JJ EL844
8/22/11 - EL844 update! We now have hundreds of players using the JJ EL844's in dozens of different brands of amps and the feedback (ya I know...) has been very positive. One of our customers (Frank Conti) even made a youtube clip of the EL844's in his Avatar 18 watter. http://www.youtube.com/watch?v=jy9cHR5NHWE
3/10/11 - As many of you know we do not participate on forums and the content on this page is precisely why. We prefer to spend our off hour time playing and writing music, along with constantly experimenting with, and chasing tone.
The statements and quotes from other sources on this page were taken from open forums. This page is not meant to hype the EL844, it is simply to answer a few questions and poignantly point out, that not everything you read on forums is true.
Seldom have we seen, if ever, the commotion, speculation, accusations and onslaught of uneducated closed minded opinions that we have seen about the JJ EL844.
We have answered a few of the many questions about this tube over on the "What's New" page, but the shear volume of questions and forum posts that our customers have sent us links to, made me feel that devoting a page to the now hotly debated EL844 was in order.
I personally find it amazing how people can profess to know everything about something they actually know nothing about? I thought politicians had that market cornered?
On to sharing the love! The first screen shots are from the "music-electronics-forum" and the "Marshall forum".
We obviously have rubbed this gentleman the wrong way (sorry about that!) but what is blindly forgotten / ignored in the above statement is that the EL844 was designed to survive the voltages that EL84's see in today's fixed and cathode biased amps. This was not an easy thing to accomplish, there were a number of prototype designs that did not survive or survived but did not sound like an EL84.
I have said many times in print that I personally am NOT an electronic design engineer or tech by trade, however having a decent working knowledge of how and why tube amps work is not rocket science. I do have many years of "gained by experience" understanding, and a lot of what I have learned was done by doing what others said could not be done. A closed mind is a terrible waste...
During one of our trips to the JJ factory we were asked by JJ "so what do we do next?" My answer, can you make us a tube that will drop into an EL84 based amp that will saturate, or distort earlier. It took a fairly extensive conversation for my idea to take root, but after explaining that we get a countless number of calls asking if there is a way to get the 15, 20 and 30 watt EL84 based amps to breakup earlier, JJ understood and the R&D started.
There have been endless comments about the EL844 being an EL83 or a russian 6P15P variant, or even a 6CW5. Again people, for the record, the EL844 is a new production tube. The plate is extremely similar to an EL83 but that's where the similarity ends. Got it?
For open minded people, think of it this way, all tubes of one flavor such as an EL84 will draw, pull, have - or what ever word you feel is correct - differing plate current values at specific voltages. If this were not true then you would not have to adjust your bias or even match tubes. You can find references all over the net about being able to run a lot of 6L6 based amps with 6V6's. Most new production 6L6's will dissipate enough heat to make between 50 to 60 watts from a pair in push pull, or lets say 25 to 30 watts each. A pair of 6V6's in push pull can make between 25 to 30 watts or roughly 14 watts each.
So now for the billion dollar question! Why can we setup a 6L6 amp like a Fender Hotrod Deluxe with a pair of 6L6GC's, bias it at 70% of dissipation and then be able to swap the 6L6GC's out for a pair of 6V6's and drop the output of the amp from right at 40 watts down to about 25 watts WITHOUT adjusting the bias??? Wait for it........... WHAT!!!! THAT CANNOT BE DONE!! BLASPHEME I SAY!!! OFF WITH HIS HEAD!! EVERYONE KNOWS THE EARTH IS FLAT!!
If you have spent any time on this website then you may know that my favorite saying of all time is "Man who says it cannot be done, should not interrupt man who is doing it" I think I may change this to "Man who says it cannot be done, should not interrupt man who has been doing it for well over a decade..."
Back on point, by selecting the right grades of 6L6GC's and 6V6's you can indeed setup the amp's bias to simply swap these sets of tubes and decrease the power the amp makes. A simple fact. Again, if the bias is properly adjusted to begin with for the 6L6GC's, then the bias will go from about 40mA (average for an HRD) with the 6L6GC's down to about 24mA with the 6V6's. What happens to the plate voltage? It goes up by about 10 to 15 volts with the 6V6's. Does the HRD distort from the power section earlier? Yes Jon, it does! With 6L6GC's and average output pups an HRD will start breaking up at about four to five on the dial, but with 6V6's the same amp will breakup up at about three to three and a half on the dial.
This is not a huge difference but when you're looking to hit the sweet spot a little sooner, thousands of our customers who have been using the JJ 6V6's in HRD's since early 2004, will tell you just how well it works and sounds.
So let me state this again in simple terms. If the bias is properly adjusted to begin with and the right grades of 6L6GC's and 6V6's are used you can replace a tube that can dissipate 30 watts with a tube that can only dissipate 14 watts WITHOUT adjusting the bias and the result is a lower power output. Tubes are simply valves, using a smaller valve will result in less power when done right.
Now let me open a few minds. Replace an EL84 that can dissipate 14 watts with an EL844 that naturally draws less plate current and can dissipate 9 watts. What happens? The bias will go down when measuring the EL844 and the power output of the amp will be less because you're running a 9 watt tube. Just like the 6V6 made less power than the 6L6GC made in the same amp.
Some may be able to call the terminology I just used "incorrect". Please remember that when you are explaining something to a large group of people with varying degrees of technological vocabulary, generic terms that are easily understood are best.
Aspen? Please.... Oh, and the shot depicting me killing Jesus Christ, it is in extremely poor taste, but after thinking it over I did get a serious laugh out of the extent someone went to, just for me...
The next screen shots are from the Dr Z forum.
These posts really astounded me! Anyone who has the ability of sight can look at an EL844 and easily see that it is not even remotely close to an EL84. Professing a tube to be a "substandard EL84 from their regular product line" or defective without ever even looking at one? Without testing one? Without listening to one?
I personally never give an opinion on anything unless I have done the necessary research to give a valid honest opinion.
Speaking of honest opinions based on real research. Mike, I salute you! I do agree with you that the volume difference is slight but when you are looking for a little drop in volume, and or a little variation in tone it's nice to have a choice. We retube quite a few of your amps up here in Oregon and several are now running the EL844's and so far every owner has said the more they play them, the more they like them!
The only thing I can say is that you paid too much for them! We have them at 22.00 a pair.
For those reading this page who do not frequent the Z forum here is a review on the JJ EL844 from a user.
The final screen shots are from the "Gear page" forum.
Update: I was asked on 04/08/11 to remove the screen shots from the "Gear Page" I checked into the legality of screen shots and found that anything available to the public can be reposted as long as credit is given to the source. However, I have elected to copy the actual quotes from the screen shots word for word. The last thing we want to do is cause any trouble or ill feelings with the good people that give musicians a great place to go like the Gear Page.
Gold Supporting Member
Originally Posted by mark norwine
I'm confused. If you want a "lower (output) power' EL84, you reduce the transconductance, not the plate dissipation capability.
Yep, just like weak, worn or new tubes that don't quite meet the spec. Oh wait!!!
KCA NOS & NEW Production Tubes & Amp Repair/Modifications.
A EL84 with lower dissipation?
I hope people realize they will need to re-bias even cathode biased amps to use these. Givin how most amps run normal EL84's at abusive settings, I can already smell the smoke!
Gold Supporting Member
Originally Posted by mark norwine
Why would *anyone* want an EL84 with a LOWER dissipation capability?
Because JJ tells them these tubes will break up earlier.
I wonder how they'll work out in 95% of EL84 amps that run the power tubes at 120% of max dissipation or higher.
KCA NOS & NEW Production Tubes & Amp Repair/Modifications.
Gold Supporting Member
Actually tested: JJ EL844
First things first: If you don't have adjustable bias, forget it. The stock bias in a PJ is - 10.5V, which causes a typical pair of JJ EL84s to idle at 10 to 11 watts.
When you apply that much bias voltage to an EL844, it all but cuts off the tube, sounding very raspy. The EL844 is a 9 watt tube, so a good idle for it is 6 or 6.5 watts. To get the tubes to idle there, you have to reduce the bias to about -7 volts.
Once you get it biased correctly, it's a sweet-sounding tube. Not as much bass, but clear trebles. It's a little quieter, but not much-- Which figures. You're seldom running your output tubes all the way open; most of the time our amps are just putting out a couple of watts. The rest is there for headroom and low notes.
Although JJ rates the filiment at 760mW, pretty much the same as an EL84, the envelope runs cooler.
I think this would be a good reverb driver tube, maybe a good low-watt single-ender. But as a replacement for a push-pull pair of EL84's, I don't see much point. I was going to offer them to my customers (who already have adjustable bias or will be installing it), but I don't think I'll bother.
One different thing about the construction: The plate wraps around the grids on three sides, like a hot dog bun. You can look and see the grids. What fun. :P
Originator and purveyor of the Billm mods for Fender Blues Junior:
Sidebar: Again, if you really want to be recognized as a person with a relevant opinion, might I suggest holding off on writing reviews and opinions until you have actually tested, or at least test driven the product... By the way, the Dr Z amps used to test the JJ EL844's are cathode biased amps.
As many of you know we have nothing against BillM. We have heard some of his tone stack mods and thought they would suit quite a few players. However we make no bones about the fact that we disagree when it comes to bias. Case and point, there are literally hundreds of thousands of Blue's and Pro Junior amps roaming the planet and the vast majority of these amps are dead stock. Fender designed these amps to run hot because they sound good like this. We do use cooler grades of EL84's in these amps because hotter grades will be close to 120% of dissipation which is pretty extreme, and more like you would see in cathode biased amps.
With cooler grades the dissipation is around 80 to 90% and the tone is still warm and juicy. In our opinion the bias does not need to be modded if the right grade of EL84's are used. We have thousands of customers getting a year or more from JJ EL84's in stock Blue's and Pro's.
The JJ EL844 is designed to drop into a Blue's or Pro Junior without worrying about the bias. The EL844's draw less natural plate current so the bias will drop to an acceptable level.
I would like to compliment BillM for actually researching the EL844 before giving his opinion! It varies from Mike's (Dr Z's) opinion where he felt the low end was fuller and the top end cut was a bit less than an EL84.
Ah, opinions, great stuff!
To date we have a lot of our customers using the EL844's in Blue's and Pro Junior amps, Orange amps, VOX amps, Dr Z amps, Marshall amps and Peavey amps to name a few. They are a nice alternative and a little different flavor for players looking to drop the output by a couple of decibels.
Are we there yet??
Yes, we're there. Last words.
We spend time during our research with different tubes and combinations of tubes to note what we like and would like to hear in the way of new tubes. The good folks at JJ Electronic have been extremely good to us about responding to our requests for new production tubes. The 6V6, the KT77, the KT66, the EL844, the JJ 5U4 and 5Y3. These are Just a few of the tubes we have requested and seen come to market over the years. I can't say enough about how thankful we are here at Eurotubes to have the ear of one of the premier tube manufacturers in existence! Very humbling.
We spend our time helping players get the tone they want and answering questions they cannot get from other vacuum tube resellers. In our spare time we thoroughly test different tube combinations in literally hundreds of different amps to find out what sounds good, bad and indifferent. Have you ever played an amp using a pair of KT88's and a pair of KT66's? Have you played on using a pair of 6V6's and a pair of KT77's? Or maybe 6L6GC's and E34L's? We have!
You can find over one thousand customer reviews here from players that have felt it necessary to take the time to put their opinions in print and send them to us.