Tube el34

Hello, I'm in the process of upgrading my tube on a Conrad-johnson cav-50. I used Electro-Harmonic at the moment. It is possible to by Match Quad of them. Witch el34 out there is the best sounding? Mullard el34? There a process of cryogenic blabla to -300? is it good?

Thank you for your time

My current favorite EL-34 is the Tesla EL-34LS made in Slovakia.
I think JJ's are the new Tesla's.They can be a little bright depending on equipment.The SED "C"logo took over the original Svetlana Made in ST.Petersburg,which is preferred by most audiophiles over the New Sensor Svetlana's.The SED's sound rich and liquidy.Matched Quads should be available in the SED "C" logo,or JJ's .The Cryogenic freezing doesn't have my friends or myself sold.The SED's are also called Winged"C" SED,s. They are both musical for modern tubes also.
A good friend of mine and I are both sold on the new Gold Lion KT77s (new Russian manufacture) as EL34 replacements. He's using them as output tubes; mine are driver tubes in SET monoblocks. Both of us had been using "Holy Grail" Mullard xf1 EL34s prior to switching to the KT77s and find the KT77s way better sounding in all respects after 8 months in his case and 6 months in mine. Just a thought. Dave
I'm using EH EL34s in my Modified ST70. I tried the SED's, new Mullards,Sovtek current and older vintage, Tunsols, New and Old Teslas, and the winner is EH EL34's. The old Teslas are really the best of all but so hard to get. The SED's were clean and quiet but lacked life and bloom and high end extension (to my liking). The Mullards were BLAH, just boring just like the SED's. I just epent $90 on a matched Quad. The older Sovteks were pretty good but they lacked dimensionality. The Tunsols were pretty much the same as the others BLAH. No excitement!
The EH's in my circuit has top end extension, excellent midrange, clean sounding but bass needed a little more control.The entire audio spectrum is better than all the other tubes. I did the same test on a friends ST 70 with the Triode input board with the SED's in the first round, then the Sovteks, and then Mullards (new). I then put my EH's in there and it was a night and day difference. I do suggest whom ever you buy them from that they do their own testing and give you a warranty. My last 2 sets or EH EL34's matched quads were purchased from Jim McShane. They lasted 2 years. I just bought a new set. All but one tested
good and I noticed the channel imblance in my amp. That's my amps way of letting me know when a tube is weak. I have been living with it for nearly 11 years. I have tried to replace it with many much more expensive amps but none were able to. My ST 70 requires a match Quad. No other configuration will work well in it. I'm dying to purchase a Matched Quad from Jim McShane of Gold Lion KT77's. They may sound better than the EH's but for the $$ how long will they last? If I am to spend $200 to $400 on matched Quad it better last as long as some of the NOS back in the day. So, why spend $200 to last me only 2 years when I can spend $70 and it last me the same lenght of time and I get 98% of the sound for less money. Same for NOS I can't justify the extra $$$ if they don't last longer. I'm not sold on cryo either! Google Jim McShane you won't regret it. Ask him about his warranty too.
Thats my 2 cents worth.
Contact Kevin at Upscale Audio, tell him what equipment you are using and your taste in reproduction(which varies widely, person to person) and he will hook you up. His matching, testing, and burning in procedures are second to none(as is his customer service). (
I always get a kick out of people who rant and rave about how good the Dyna ST-70 is. It is a nice sounding amp, but certainly no world beater. I owned one back in the day that I picked up from the original owner in beautiful condition. My next tube amp after that (this is going back some years)was an ARC D-76. The D-76 is so far superior to the ST-70 that it is like compairing a boy to a man. The poor ST-70 was a wimp in comparision to the D-76.
Let's see- You're comparing an amp that was introduced around 1960, and rated at 35WPC(actually more like 17WPC in reality) with one that came out in 1974, sporting 75WPC. Gee- I'm amazed that there was such a difference in their performance!! There have been numerous upgrades and mods offered for the ST-70. Many that truly improve it's output and presentation. It doesn't take much to bring one up to the level of performance of today's amps(of equiv. power). I enjoyed mine for quite a few years(performing my own mods), as the mid/high amp in a bi-amped system. BTW- The production of the ST-70 almost reached 300,000 units. A pretty popular amplifier it seems.
thank you for all this info. Maybe i will stick with EH el34. People says that they lacking bass control. But if they are musical it fine for me.

What do you thing of the paste for the connector? is it good? Do you know groove tube gt-el34?

thank you again

pete dogy
There was a blind shoot out of EL 34 tubes done by golden eared blindfolded audiophiles by Vacuum Tube Valley a short while ago of a total of 15 different EL 34 variants including Mullards, EH, etc and new and NOS Original TESLAS and the original NOS TESLAS were the hands down winner and blind favorite. Unfortunately they are hard to find and increasingly $$$.
I have used the original Tesla E34Ls for almost 20 years, and still have enough in reserve(not for sale, by the way) to last me for some time. I also have a good number of the later issued JJTeslas, and yes, I have compared the two, and also feel the originals trump the JJs in the areas of slightly greater clarity and top end detail and deeper, more controlled bass. I also have a dozen Siemens made AEG EL34s, which though nice sounding, don't quite give me the balance I like with my original Teslas. At about the time I purchased those Teslas, I tried Svetlanas, but have never listened to the more current Winged C Seds. I attributed the same characteristics to the Svetlanas as Ponnie has to the Seds---not involving enough and lacking top end extension. I have not tried the EH or any of the Mullard EL34s, and cannot use KT77s in my Air Tight amps. Of course, these are my impressions utilizing my componentry. As they say, YMMV.
I recently purchased 2 quad of el34 Tungsol for my prima luna 6 mono blocks, and I am quite satisfied.
I just put 8, EH EL34's in my Cary CAD 120S amp just to try them out. I was using the new issue Gold Lion KT88's previously so this will be an interesting comparison. I thought the Gold Lions were great by the way. Maybe just a little to warm for my Harbeth speakers that are also on the warm side.
NOS Mullard, Siemens or Telefunken rule IMO. OLD Tesla were robust and made to last, don't know if the same could be said of the new. It is a scientific fact that cryogenic treatment is futile unless you use HUGE magnets to orient the molecular grain structure of the metal components in the tube at 0 degrees Kelvin. Something like a MRI scanning magnet should suffice. This orientation that actually does have some performance benefits to electron flow will be affected adversely as soon as the valve is heated in use. I suspect therefore that the benefits would be marginal at best. Aside from perhaps stress relieving the tube. The benefit is I suspect to the tube sellers in the way of value adding.