Anyone used Sovtek 12ax7wa - Had one crack

[CoopDaKill]

I bought a quad set of the Sovtek 12ax7wa tubes from Ebay,from a good seller with an even better reputation. I put the tubes in my Peavey XXX Head and they sounded good, but then became very microphonic within a few minutes. My amp seemed to have to have more gain than normal. Then the volume went out, I could barely hear the guitar. Well I checked those Sovteks and I discovered that one of them had cracked from a pin, ran up the side, and of course lost vacuum. My question: Ya think I just got a bad tube? Or, are these tubes sub-standard. 4 of these tubes were $22.99 & free shipping. Please give me your thoughts. Thanks ....

[Jazz P Bass]

Kind of hard to decide where to place the blame.
Sovtek generally makes decent preamp tubes.

[CoopDaKill]

Yeah, I feel the same, Jazz P. I know the ebay seller gets them from New Sensor. I've never had a Sovtek fail. Maybe I just got a bad tube. I did have a new Tung-Sol reissue do about the same thing a few years back. It lost vacuum too. Would you buy from this seller again? Thanks for your reply.

[JoeM]

Did you contact the seller? I think you just had bad luck with one tube.

[Chuck H]

The Sovtek 12ax7wa is generally a rugged tube. I've had them HUMMMM right out of the box a couple of times. And I think they sound like a blanket was thrown over your speaker cabinet. But those are different issues. I've never broken a tube. And I've used a lot of tubes from Sovtek and others. That you've had similar problems with two different brands does raise an eyebrow. Were both of these failures in the same amp? Same socket?

[CoopDaKill]

Different Amps, and different tubesfrom different sources. The Sovteks were not packed very well, I noticed when I first opened the box. The seller used one little piece of newspaper as cushion. With that said, It's possible that the tube may have suffered a small hairline crack during shippng, and was not noticed before install. But, ya never know, anything is possible .

As for the sound of the Sovtek 12ax7wa, they seem to work well in the XXX amp. Nice tube saturated sound, for the metal tone.

[Chuck H]

I'm not bashing the tube. It just has a sort of dull tone. I'd never put one in a vintage style amp. But I do have a design that specs the Sovtek 12ax7wa as V1. With it's small top end deficiency and extreamly low microphonics it just happens to be "right" for this amp.!.

[1ampman]

I've installed quite a few Sovtek WA's. I had several news ones that had hum, noise, and just didn't work. It's no fun sending them back but I do. My feeling is they just don't test them fully in the factory. The buyer ends up doing the burn in and that's where all the problems show up. I still use them and they work very nice in certain amps. Some dealers buy them in bulk and probably don't have time to check them before shipping out... I don't see suppliers spending the time to test a $10 tube... I wonder how many people don't ship them back for a replacement???

[Chuck H]

The last batch of five I ordered had two hummy tubes. I intended to, but never got around to sending them back. It still kind of irks me that I let it slide. I'll just stack them on the pile with any other regrets

[Enzo]

I think that when you get ONE cracked tube, the first response ought not to be thinking that ALL of that type are ready to fall apart. If I look at the sky and see a 747 jet with the Space SHuttle on top of it flying over, I don;t think geez 747s all come with Space Shuttles these days.

ANY tube can crack, any tube can face physical stress in shipping. And remember that these tubes have been shipped and shipped and reshipped multiple times before they reached you.

[Chuck H]

And remember that these tubes have been shipped and shipped and reshipped multiple times before they reached you.

And you can still buy them for under fifteen bucks!?!

+++ on the analogy. As I said, I've never cracked a tube. and I go through a few more than the average player. Maybe I'm overdue and the next three will crack on me