Sovtek EL34 Mullard Reissue Power Amp

The Mullard reissue El34 looks EXACTLY the same as the Svetlana EL34 and the ElectroHarmonix EL34. I know they are all made by Sovtek, but they are all priced differently. I wonder if these are all the same. It may be that Sovtek tests them when they are done and labels the best ones "Mullards." I don't know.

These tube do sound good. They are very balanced sounding I would say. I have also tried the Electro Harmonix el34s, and it's tough to tell the difference.

These have been reliable for me. No problems so far.

Customer support is o.k. if you contact New Sensor or, I guess, Electro-Harmonix, since they seem to be related to Sovtek somehow.

These are good tubes, I just which they had the double halo's like the Winged C El34's have (maybe they'd sound better with an extra halo, who knows). And I wish Sovtek would explain what the difference is among the Sovtek, EH, Svetlana and Mullard. It's tough to spend twice as much and be wondering if you are getting exactly the same tube!!!

Sovtek (Reflector) "Mullard EL34 Reissue" power tubes. Installed in Marshall 1959 100w head & 1987 50w head.
No real features except the implied relationship to the vintage Mullard EL34.

These "reissue Mullard EL34" power sound good but do not sound like Mullards (I've got several sets of various production version of actual Mullards as a point of reference).

These tubes have a good bottom end response w/ a bright, crunchy top end. In the Marshall non-MV amps where I used them they sound quite good but certainly not as detailed & 3D sounding as real Mullards.

Here's where the problems begin. There sems to be an issue w/ these tubes when driven hard (as in the Marshalls) because they randomly exhibit plate over dissipation symptoms (dull red plates) no matter how conservatively they are biased. I've got a matched quad and a pair of Watford Valve Harma Retros and both sets have one tube that exhibits this problem over a broad range of bias conditions. These tubes have been run at quiescent power dissipations ranging from 11-15W in the Marshalls and there's been no change in the over diss problem. All the screen and grid stoppers resistors are Ok and as a check I've replaced these tubes with JJ EL34, Winged C, EH, and the Mullards in the same amps, re-biased, and all is well. There's definately something amiss w/ these tubes wrt quality!

The local shop and Watford Valves stand by their products and will replace a failed tube. Unfortunately there's no assurance that the next tube will not have the same issues!!

The local shop and WV get a 10 for support but Sovtek gets a 1 for fielding unreliable product in the first place whichs gives a 5 for this category.

I've been playing guitar for over 20 years and servicing tube gear for 25 years. New tubes introduced to the market are always suspect until proven by several years of service. Unfortunately Sovtek didn't wring these EL34s out well enough from a reliability standpoint and are consequently not doing justice to the good record that Mullard established.