EL-84--Sovtek vs. J.J ??

Hi Brian,
I'm in no way affiliated with JJ but I can tell you the difference will be huge it'll definitely thicken your tone. Visit www.eurotubes.com and give Bob a call or e-mail him. He's the man and can definitely recommend what you should do.Still,IMHO JJ's are one of the best (if not teh best) in production tubes and way better than Sovtek's.Give 'em a try and let me know what you think,

Vlad

 

Hey Brian,

that's possible too.I guess you had a faulty tube.I don't know where you bought it from but still call Bob @ eurotubes.com and talk to him he'll definitely help plus don't forget that you might have to rebias your amp after changing the tubes.

Vlad

 

Hi Brian,
as far as I know there is no such thing as direct replacement for tubes on amps with adjustable bias.When you change your power tubes you will always have to adjust the nias more or less no matter what brand of tubes you're swapping with.That said,taht's why I advised you to contact Bob because he knows all about taht stuff and if you are not comfortable with biasing your amp you're gonna have to get it done by a tech or someone who knows how to do it.Let me know how it goes.

Vlad

 

The amp is cathode biased, which means it's self biasing, but probably fairly hard on tubes, particularly if it's based on the Vox AC-30 design. Class A is a descriptor of a tube's operating conditions over the duration of a waveform, and has been misapplied as a marketing word, to lots of amps that might run in class A once in a while. What you have there is a cathode biased amp.

I've used both Sovtek and J.J. El-84 in my Guytron which configures them cathode biased. The Sovteks to my ears are a little harder and brighter sounding right away, and deteriorate more slowly than the J.J. tubes. I prefer the J.J. tubes, sonically, smoother, but with detail where you want it. The problem is that the Guytron can beat them into the ground pretty quickly. I've had pretty good luck with some tube vendors supplying tubes selected to draw somewhat lower current, which lengthens the life a bit. Lord Valve has done this for me.

I've had both brands give up the ghost, loss of vacuum with Sovtek, but with the J. J.s they dwindle until the amp just has no headroom one day, I swap em out, and it's back to normal.

The Ei El-84 are well thought of by some of the Vox fans. Which ever way you choose to go, use a reputable vendor like KCA or Lord Valve, or Euro, etc. cause for an amp like yours, they should be screened and qualified for microphonics etc. It's worth a couple bucks extra. You might even want to get a few quartets and do some listening, see what you prefer. They are inexpensive relatively speaking, and it's fun to do.