Mullard EL34 as a choice for your amp.

I am hearing that those EL34 are one of the best if not the best tube in this family. True or false ?


I am asking in regards to my Consonance Cyber 800 mono-blocks. It seems like a costly investment. Is it worth it and why ?


El 34s are GREAT for small, intimate music. However, they don't rock and they don't do large scale well/

Thanks to ICE technology (at least when it's done right) you no longer need tube amplifcation. See Wyred4Sound amps

You might gain tube warmth from a tube preamp or tube output of your source
Are you talking NOS or reissues?
Mrjstark-- congrats on having a very nice set of mono's.
As configured--each of your mono's with a quad of EL-34/6CA7 are capable of some major dynamic swings and LOUD playback levels with rock and large scale music. This is especially true if your speakers are above 8 ohm impedance and 91db efficiency. Many of the great guitar tube head amps use EL34's and believe me when I tell you--they rock.
As far as Mullard old stock tubes are concerned (not re-issues) they are known to last many thousands of hours as well as having a more tubey old school sound than the more modern production. I would recommend some of the newer production tubes for you as two matched quads of original Mullards will run you Approx. $800.00 The new Groove Tube Mullard reissue are claimed to be very good. It would be a good idea to state the type of sound you are shooting for.
Tweak1 , addiction is stronger - thanks & sorry but will stick with tubes for now. I also think that there is a huge misunderstanding on the characteristics
of new and old/vintage sound of tube gear. But that issue was beaten to the ground and opening this can of worms will take away from the actual question in hand. Some of non tube gear that I like are: DarTZeel gear (nice but price is beyond me) and
Red Wine Audio Signature 30.2 amp - which I really like and see myself building a system around it.

Hi Rob,
no I was thinking about NOS,
heard mixed feelings about new reissued series.
But please, share your thoughts regardless.
I am always open to good advice or suggestions.
Thank you Jig for complements and interest in my question.
You are right, I should mentioned the characteristics that I'm looking for in EL34s replacements. My rig is already fast, transparent, musical. Bass is nice, well define, articulated, robust and I am not sure if it can get any better in my own setup and room. So, where I am looking for improvements is middle range. What I am seeking for is more engaging voices, slightly more body and air around the notes, detail (not coloration). Budget around $500.

Also anyone came across low noise, musical 12ax7 for phonostage.

Thank You
I recently bought Vacuum Tube Valley issue 16 to research the "which EL34" question, as it had an EL34 tube shoot-out. Apparenltly here are 3 different types of Mullard EL34's, of which type 2 and 3 rated very well, but they rated almost all the new production types (JJ E34L, Sovtec EL34G, Svetlana EL34) equally well, and several NOS Tungsram tubes better. They liked some 70's Japanese Amparex the best, surprisingly some Telefunken among the least, but almost all the tubes rated pretty closly. I use late Siemans, and like them.
A friend of mine has those amps with JJ KT77s on Martin Logan Odysseys and it sounds FANTASTIC! I would look into some of those JJs
JJ Tesla's are great EL34s and to me sounded better than NOS Mullards in my Quicksilvers. They're less colored and have wonderful detail.
Stivervii, the JJ KT77 are NOT compatible with the Consonance Cyber 800 tube monoblocks. And, despite what some try to tell you, neither are 6550 and KT88. This is the price paid for the convenience of this cathode bias (autobias) circuit.

After CES2008, the owner of Consonance stayed with me for almost a week, and was astounded to find my assertion correct, as he was sure the amps could run the other tubes. Believe me, I'm a tube roller, so I've already tried as many combinations as I felt worthy of trying. He felt the reason for it is perhaps in the way the amps behave on 110/120V AC. We may address this going forward, though due to other projects having priority, it will not happen soon. If your friend's amps truly does use them, he must certainly have a pair with different values in the bias resistor positions. Otherwise, it's July 4th any day of the year.

Unfortunately, Mariusz, NOS Mullard tubes command a prince's ransome - Mullard KT77 being a king's ransome. A few of us in my audio group got together over a period of several sessions (using different amplifiers - Jadis, Granite, Quicksilver, Consonance) and performed a tube shootout between 1960's vintage Mullard EL34 XF1, JJ Blue Glass E34L, JJ Clear Glass KT77, and JJ Blue Glass KT88. Another party also included the EH EL34. The intention was to determine whether any current production tube could displace the Holy Grail that the Mullards have come to be considered.

The winner was the Mullards. They performed best from top to bottom. The JJ E34L were voted best when price was factored into the equation, and some folks rated their midrange best in a few of our scenarios. I don't want to give anyone the idea that the JJ E34L sounded like the Mullards; they did not. The weak point of the JJ EL34 was the definite lack of extension and power in the bass, for the KT77 it was the recessed midrange (though, some also didn't like the overly fat mid/upper bass, which they felt out of balance with the rest of the musical spectrum), and for the KT88 was every area other than output power.

But, I agree with Nickword's suggestion of trying JJ E34L tubes to get where you are trying to go, Mariusz. Though the JJ E34L is my favorite current production output tube in audio, as things are with the stock amps, switching the EH 6CA7 out for them does not yield improvement, in my opinion. The very slight gain in the mids is more than offset by the lossess in overall power and the low frequencies - extension, impact, and definition. Your amps being modified by Bob Backert however, may behave quite differently in this regard than the stock products, and produce the results you are looking for.

One note of caution, however, is that the reliability of JJ output in general is eye opening. Because of their sound, I was pushing Consonance to use them instead of the EH (apart from the 6CA7 in the Cyber 800) tubes used in most of the products. Testing proved that this was definitely not the way to go (I don't want to get into the numbers in terms of failure rates here), though the Consonance Cyber 100 Signature KT88 15th Anniversary integrated is using them. If one of your amps encounter a bad output tube, it will definitely go down, and you'll be taking it in to either Bob or me for service. I've had amps in for this repair, and in both incidents, the output tube the customer used was the JJ E34L.

DISCLAIMER: I am the importer/distributor for all Opera Audio/Consonance products for the USA and Canada
Thank you all for your thoughts and recommendations.

The fact is that I own one set of 8 replacement JJ Blue E34L tubes for over 2 years now. I have tried those tubes briefly (about 20h total play time) with Cybers 800 and they were quaite nice. However for the same reasons that Joe (Trelja) mentioned, I am being really caution and kind of reluctant to use them while risking the mishap or worst.

very good point on Bob's modification and its characteristics. There is a stark difference in bass, speed and transparency in comparison to original (not modded) version. How the amplifier is going to behave with variety of EL34s is only my guess. My biggest concern is comparability, safety and of course musicality (especially in the middle range area).

Consonance Cyber 100 Signature
is looking good....very nice)

Thank you for the compliment on the Cyber 100 Signature KT88 15th Anniversary amplifier, Mariusz. I appreciate it. I should have the first coming into the country next week, and feel quite excited about it. It basically represents Consonance's all out assault on building a tube integrated (pure Class A operation, upgraded power supply, special caps, and I would presume, better (amorphous?) output transformers). They claim SET performance out of a push-pull amplifier, so I'm curious to see what they can turn out when swinging for the fences.

So long as you give the JJ Blue Glass E34L a truly thorough round of testing, I would not hesitate to use them. Again, they are my favorite current production output tube, and I personally believe they can create a magic in the midrange that is almost without rival. In my Jadis DA60 integrated, that was the case, but it was a toss up as to whether or the powerful low frequencies the JJ KT77 produce. Not until I found the right compliment in terms of a 12AX7 driver for the E34L, which added the thunderous bass to that magical midrange, was I totally satisfied.

It sure would be interesting to see how far the amplifiers with Bob's modifications can stretch out with such a tube. One never knows until they try, but they may well prove mind blowing.

Personally, I advocate fuse protecting an amplifier at each of the output tubes the way my Jadis DA60 does to take into account the fact that there exists an element of Russian Roulette in vacuum tubes. It's an incredibly cheap insurance policy. Folks against it argue that one cannot help but pay a sonic price. I can't say that you don't, though hearing the Jadis leaves one to wonder how much better things could get without such protection. Haven't tried upgrading the fuses yet, which given the location of them I believe must make a profound difference, but I will at some point.
I will give them another chance but not before a check up - will try to find someone locally.

It will be interesting to hear Sign. 100. If someone is looking for integrated amp I would recommend it even without audition (which is foolish and not responsible) , yes I am really confident in this product.


I'll add this - Mullard is the original designer of this tube and set the standard as well. It started with xf1 series, and the xf2's are very close in quality, but hereafter the decline begins.

I have yet to hear a tube surpass them, although some come very close - The earlier, original Czechoslovakian Tesla's, and the older, original 1990's Svetlana's are 2 that come to mind. These stand out not only because of sound, but quality of manufacture and longevity.
lots of recommendations ( truely helpful ) , thanks.
From what I read here(& elsewhere) Mullard is the tube of choice if money was not a factor. JJ new/Tesla-nos and some Japanese Ampares (from 70's) not far behind.
Now, Joe said that new JJs have great middle range (weaker in bass) , what about the others??? What they sound like. Anyone cares to shortly describe the sound characteristics, lows & highs of that particular tube.
That would be very helpful in narrowing the choice of tube for specific application and use. Price range would be also appreciated .

The New Sensor version of the KT77 is due out shortly...if by experience it can duplicate the quality of sound & reliability of their "KT88 Gold Lion Genelex Reissue" they will have another option worthy of consideration...
Enjoy your music!
I think that KT77 are a NO NO for my amp.

Thank You &
enjoy the music