Are Tung Sol 12AX7's inconsistent?

[Mickey64]

After reading a few reviews of the reissue Tung Sol 12AX7, I bought a couple to try from a reputable UK dealer, but they hum so obviously to me that I can't really use them. I put them in V1 and V2 of my '57 Tweed Twin reissue, and although they certainly sounded very musical, I've ended up putting the stock Groove Tubes back for the time being. I've actually used 12AX7EH's for years with very few problems, and thought I'd try these instead, but I'm disappointed. I'll admit one is worse than the other, but are they really that inconsistent?

[Mercury25]

I bought 10 Tung Sols from Tube Depot last year--7 of them were returned due to problems.

They replaced them after I paid to ship them back--after they tested them and said only 1/2 the tube circuit was working...

[pgissi]

Have not bought any since 2007 and when I did bought 1 dozen, only 1 was noisy.

Guess 2008 was not a good year

[peaky]

Yeah, I too had problems with the Tungsol's. I bought some a while back and all three went on me very quickly, sounded thin IMO and were noisier than others I've tried. Not impressed :mad:

I'm sick of wasting money on valves, so now I'm sticking with JJ's all round. I've had really good experiences with both their pre-amp and power valves. They sound good, are reliable, consistent, easy to get hold of and cheap.:AOK

[Mickey64]

Thanks, well I'm going to send them back, or at least change them for something else. Now I just have to convince the dealer; I'll probably go back to EH's, they've worked for me.

[VanR]

I always think I'm gonna have to try those Tung-Sols out but never order any. I'll just stick with my RCA 12AX7A's and Chinese 8th and 9th.

[WaltC]

when they work they sound great. for me my reject/failure rate was over half and I can't afford that kind of reliability when I'm dealing w/ customers so I just use JJ's, which have been very consistent and reliable over the last three years or so for me. I've also successfully used chinese (not as unreliable as TungSols but not as good sounding as TS's or JJ's) and Sovtec 12AX7wa's (which many folks don't like but have been pretty good for me) and LPS's which I like for P/I's and reverb recovery. I don't think EH actually makes any tubes, aren't they just relabeled Sovtecs? (don't remember for sure, just vaguely recollecting...)

[sfarnell]

I'm a recent convert to tung-sols and haven't had a problem. They are relatively noisless and VERY musical. I've only bought four, but so far, so good.

[dtube]

I buy mine directly from New Sensor and haven't had a dud yet. But, I've only used probably 15-20 in the last couple years. Now I'm concerned about the remaining 10 from my last order - time for some thorough tube testing...
-Darren

[TweeDLX]

I bought 6 Tung Sols a year ago for my Concert II. Love the sound, and no problems whatsoever. My $.02.

Mike

[WaltC]

well, I just bought 4 more new ones, so I'm keeping my fingers crossed...<g> I really like the way they sound when they work.

[Doyle]

I really like the Tung-Sol 12AX7's. They took the harshness out of the head I put them in. Very nice tubes. I get mine from the tube store.com. The twelve that I have from him are all good to go, no noise.

[Daniel-San]

I recently replaced all the 12AX7's in my Twin Reverb with the Tung Sol's and they're sounding good. No noise or other issues.
Though I can imagine, with all the inconsistend production these days, that Tung Sol has some problems too.

[Trout]

Seems like a lot of stuff coming from New Sensor, or lets say recent batches that have trickled down through the dealers are having issues.

I have a couple dozen EH12AY7's here and only 5 actually work close to correctly. I am done buying anything they make at this point.

[Blue Strat]

I test every tube I sell and have virtually no returns/problem-reports on the Tung Sol Reissues. I do reject quite a few for noise when I test them.

Note that these tubes don't hold up in "cathode follower" circuit as found in most Marshalls (v2 if the amp has 3 preamp tubes) and some other amps. Dealers who know about guitar amps usually warn customers about this. Commodity dealers (ones who know little about amps) don't because they're unaware.

[JimmyR]

Well I have tried one Tung Sol RI 12ax7 and it made my amp feedback and perform weird noises. So 100% of the Tung Sols I have tried were faulty!

I get sick of trying every new relabelled New Sensor tube only to have issues so I stick to JJs unless I come across a good NOS. I often use a great NOS tube in V1 and use JJs in the other slots. JJs aren't fantastic but they're good and reliable and cheap. And if you use the odd NOS Mullard or whatever in the right place you can get great results without breaking the bank.

[WaltC]

hmmm.... hadn't picked up on the problem w/ tung sols and the cathode follower business. Maybe that explains some of the problems I've been having w/ them.

[mark norwine]

"Tung-Sol" my ass.

IMO, if Mike Mathews is proud of the products he produces at his Reflektor factory, he should proudly print the name "Reflektor" on the products.

Buying the rights to a name, then printing that name on a product that bears zero resemblance...pretty shameful, if you ask me

(which, I realize, you didn't!)

[pgissi]

"Tung-Sol" my ass.


For me, I went into using Tungs knowing this and am aware, like many here of rebranding and was pleasantly surprised tonally from my 2006 and 2007 purchases. I think I had bought more than 2 dozen within a year and really only had 2 or 3 total out of those 2 purchases and they are still going strong.



I really like the Tung-Sol 12AX7's. They took the harshness out of the head I put them in.


I found the same and all at the same time they breathed life into 2 amps I am using them in.

IMO the best budget retube are Winged C's in the power section and Tungs in the pre. But, I have not retubed since 2007 so maybe something has happened in this last year.

As soon as I collect on Powerball, I'll try some NOS:rotflmao

[Bluesbuff]

I retubed my SFDR and SF princeton with the Ting sols and have had no problems with them.

[sickboy79]

I test every tube I sell and have virtually no returns/problem-reports on the Tung Sol Reissues. I do reject quite a few for noise when I test them.

Note that these tubes don't hold up in "cathode follower" circuit as found in most Marshalls (v2 if the amp has 3 preamp tubes) and some other amps. Dealers who know about guitar amps usually warn customers about this. Commodity dealers (ones who know little about amps) don't because they're unaware.

Seems to be a trend with New Sensor/Reflektor stuff. Doesn't the Sovtek LPS fall into the same category? Any others?

I usually use new production stuff as PI tubes, and NOS everywhere else. I have 2 Tung Sols - one when bad one me. It caused nothing but static to come through the speakers.

[Gene]

I bought like 12 of them and 6 went bad within a year or so. Not much hours on them since they were in bunch of different amps. 2 died outright and others became very noisy and added insect like buzz to the sound... JJs were even worse..

Surprisingly, I've had the best luck with the cheap sovteks and the chinese 12ax7s.

[Fred Farkus]

I heard that the issue with the tung sol 12ax7's was their max heater to cathode voltage was in the 100's whereas most 12ax7's are in the 200's. So be careful if you are using them for a cathode follower (buffer) unless your heater voltage is elevated with a dc bias.

[B Bent]

I have had shotty luck with them. The good ones are GREAT though!

[Trout]

If guys would stop buying the garbage new sensor has been dumping on us, maybe they would try harder to produce something consistant.

QC has always been horrid with these guys and the policy of selling off seconds or not to spec tubes to bottom feeders just makes the problem worse.

Just about every tube style they make has had great and horrid production runs. When they get it right, they are fantastic, but flip the coin, when they blow it, we still get stuck with them.

I feel bad for many of the tube vendors these days, they buy a bulk flat of tubes(case of 100) and by the time many of them find out from customers that they are a batch of rejects, the return period is over.

[Mastervolume]

worst f'ing tubes you can buy today

[bonertone]

We go thru hundreds of 12ax7 preamp tubes every year.
In the past years the quality has been fairly consistent and dependable (you will always have a couple bad).
But in the last 2 years the QC has slipped a noticable amount.
I dont think anything they sell is screened for noise so when you purchase case quantities it has become a real crap shoot in terms of dependability.
Buying from a knowledgable tube dealer that actually tests for noise is your best bet for small quantities.
But that is not an option in manufacturing.
The good thing is New Sensor is aware of this situation and have always willingfully replaced bad stock but that doesnt help so much if the amp is off in another country.
I think most of this started over the ROHS transition also a while back you will recall Mike was having a horrible time with the Russian mafia so maybe this has disrupted the QC who knows...
The 12AX7 EH got so bad for noise issues we had to stop using them all together at least 50% per case had noise issues
The tungsol 12ax7 was about 20% per case.
So we went to the Mullard 12ax7 (actually the LPS w/ mullard logo) and have had very little problem till lately and we are starting to see about a 10% failure rate on those...not bad but scary that the problem happens not at first but after a little time.
The job the tube does in the circuit is also influential someone earlier mentioned cathode follower circuits tend to eat the tungsol and I will agree also the other typical spot is a driver position...

[boogieplaya]

I bought about a dozen of them about 1-1/2yrs. ago and only had 1 that was a little hissy in the v1 slot. And i run them hard in my Marshalls by slamming the front-end with a tubescreamer. I really think they are very "toney" tubes too. JJ's preamp tubes are robust, but not as sweet sounding as the tungsols. Maybe qc is sliding over at new sensor.

[Trout]

We go thru hundreds of 12ax7 preamp tubes every year.
In the past years the quality has been fairly consistent and dependable (you will always have a couple bad).
But in the last 2 years the QC has slipped a noticable amount.
I dont think anything they sell is screened for noise so when you purchase case quantities it has become a real crap shoot in terms of dependability.
Buying from a knowledgable tube dealer that actually tests for noise is your best bet for small quantities.
But that is not an option in manufacturing.
The good thing is New Sensor is aware of this situation and have always willingfully replaced bad stock but that doesnt help so much if the amp is off in another country.
I think most of this started over the ROHS transition also a while back you will recall Mike was having a horrible time with the Russian mafia so maybe this has disrupted the QC who knows...
The 12AX7 EH got so bad for noise issues we had to stop using them all together at least 50% per case had noise issues
The tungsol 12ax7 was about 20% per case.
So we went to the Mullard 12ax7 (actually the LPS w/ mullard logo) and have had very little problem till lately and we are starting to see about a 10% failure rate on those...not bad but scary that the problem happens not at first but after a little time.
The job the tube does in the circuit is also influential someone earlier mentioned cathode follower circuits tend to eat the tungsol and I will agree also the other typical spot is a driver position...


Last I read, Tubes are exempt on the ROHS issue.
http://www.rohs.gov.uk/Docs/Exemptions/Exemptions%20Full%20List.pdf

[Dearthian]

I like their sound and had no noise issues, but have had failure issues as of late. I had a gold-plated 12ax7 go south with less than a year on it. Weird thing was both my V2&V3 tubes went at the same time. Replaced them and everything has been ducky. Weird.

[traviswalk]

I haven't had issues to date and use them a lot.

[Structo]

Does anybody know if the EH tubes and the Tung Sol tubes are the same tube?

Because Mike Matthews owns New Sensor and EH and a bunch of other companies.

Just curious, if the tubes are the same.
I have been hearing good things about the Tung Sol 12ax7's but haven't tried them.
I have tried several EH 12ax7's and haven't really had any issues with them but nothing to write home about.

I will add that I bought a few of the Chinese 12ax7's from Ruby and they sound darn good in the overdrive channel of my amp.
I think they are the 9th generation ones.

[rjgtr]

I've had generally good results with the "TungSols". Only a couple out of 50 or so have gone bad. They sound good in a Fender style circuit, but I tend to mix them with JJs in a Marshall style circuit. I think the Shuguangs seem to be the most reliable new production. They seems to be very reliable for both CF and PI. On the same note, I loved the tone of the GT-12ax7M, but the reliability was so bad I had to stop using them.

I agree on SED/Winged C. They are one of the best sounding and most consistant output tubes and have been even before New Sensor stole their real name (Svetlana). If they only made a good 12ax7, I probably just use them for everything.

The whole renaming thing with EH bugs me, too. It's all just marketing B.S. Maybe their own name (Sovtek) became so associated with bland tubes they thought a new label would help.

[Rosewood]

I just wish all tubes were consistently good or consistantly bad, then at least we would know.

[III]

So we went to the Mullard 12ax7 (actually the LPS w/ mullard logo) and have had very little problem till lately and we are starting to see about a 10% failure rate on those...not bad but scary that the problem happens not at first but after a little time.
Is the RI Mullard actually the same internally as the LPS?

If so... LPS tubes aren't good in cathode follower stages either, if I remember correctly.

I currently have Mullard RI in my Super Lead. Do any New Sensor tubes hold up in CF stages? Svetlana RI maybe?

[Mickey64]

Well, the five Tung Sol 12AX7's that I bought work well in my '72 Deluxe Reverb, though one is too microphonic to use in V1 or V2. They seem to thicken up the tone a little compared to EH's in that position. They don't work well in my '57 reissue Tweed Twin though, producing some hum in V1, and excessive hum in V2, the bright input tube. Maybe they can't take the voltage there, I don't know. It would be nice to have some "official" guidance as to what works where.

[Trout]

Well, the five Tung Sol 12AX7's that I bought work well in my '72 Deluxe Reverb, though one is too microphonic to use in V1 or V2. They seem to thicken up the tone a little compared to EH's in that position. They don't work well in my '57 reissue Tweed Twin though, producing some hum in V1, and excessive hum in V2, the bright input tube. It would be nice to have some "official" guidance as to what works where.


I agree but its impossible. They build a good batch, then they build a crap batch. The real problem is they dump the crap batch into the market to cut their losses.
It does not matter which tube they make, Tung-Sol, EH, Mullard, GEC. Unless somehow we convince them this is no longer acceptable, it will continue.

Back in the hayday of RCA and others, a bad batch would be destroyed, not brokered out.

[JJman]

I recently bought an EH and a JJ 12ax7 and found both to be too hissy. This was not my previous experience with them and my Ruby Chinese ones are much better. But some of my Ruby Chinese ones are microphonic whereas the ones I bought when they 1st came out are not. My used Zenith/Blackburn/Mullard remains the best in all categories.

I wonder if anyone has compiled a spreadsheet of common tube brands/names/factories/etc. It would be nice to see what tubes are actually the same, and what factory/tooling/specs each uses. If I knew these things, I would probably make the sheet myself. Some column headers might be:

Tube (e.g. 6v6)
Special characteristics (e.g. long/short plate, gold pins.)
Brand/Box name
Label name
Factory name, City, Country, and etch code
Distributor name (if exclusive)
Tooling year and engineering firm (sometimes tooling is moved/changed)
Range of years in Production (to differentiate "eras" as with Mullard, Tungsol, etc)
Known issues (e.g. “Don’t use the 2006 ones in application 123.”)

Of course there would be much overlapping as in the case where brand X had the "same" tube made in more than one country. Having one row for each full scenario would allow us to see the commonalities and the key differences. Many listings would be difficult to capture since there where behind-the-scenes deals and shenanigans with bogus labeling. But it would be nice to have all the general-consensus knowledge in one place for us all to see, at least for the very common guitar amp tubes like 12ax7.

[Mickey64]

......it would be nice to have all the general-consensus knowledge in one place for us all to see, at least for the very common guitar amp tubes like 12ax7.

Absolutely!

[aarondavis]

I just have to say this... (sure it's been said before) but....

I get real tired of the tube threads on TGP. I can never get a definitive answer on what tubes I really *should* buy. I get people casually saying, "these a great tubes" and then in the same thread the opposite response. And then the guy's that sell them just basically say... yeah this "brand is pretty good..." "Nothing compared to real NOS Mullards, Tung Sol's...etc, etc."

Please, someone that really knows tell me what the best new production tubes are. For both 12AX7 and EL84. Thanks!:jo

[Trout]

I just have to say this... (sure it's been said before) but....

I get real tired of the tube threads on TGP. I can never get a definitive answer on what tubes I really *should* buy. I get people casually saying, "these a great tubes" and then in the same thread the opposite response. And then the guy's that sell them just basically say... yeah this "brand is pretty good..." "Nothing compared to real NOS Mullards, Tung Sol's...etc, etc."

Please, someone that really knows tell me what the best new production tubes are. For both 12AX7 and EL84. Thanks!:jo

Well, that's where the problem is.

These companies are inconsistent at best. At any given moment, a great batch of brand X could arrive and people will be glowing how great they are.
2 months later, a batch of rejects arrive and guys post their negative experiences.
Currently there is simply no " Best Brand" They have all produced Cherries and Lemons and continue to do so.

The same questions are asked on other forums as well, and basically the same reply's and experiences are posted there as well.

[mark norwine]

Because Mike Matthews owns New Sensor and EH and a bunch of other companies.

No.....MM owns only one tube company: Reflektor.

What he owns a lot of are "names & rights to use them"

Does anybody know if the EH tubes and the Tung Sol tubes are the same tube?

Sorry for inverting the order of the text on your post, but I think the first response answers the 2nd question.....

I'm not saying they're the "same tube"; there may internal be differences.

But as I said earlier in this very thread: If Reflektor tubes are so great, why shouldn't MM be proud of that? Print "Reflektor" proudly on the glass, publish the [real] specs and allow the marketplace to decide. After all, JJ seems to be doing pretty well with that business model.

[rockon1]

But as I said earlier in this very thread: If Reflektor tubes are so great, why shouldn't MM be proud of that? Print "Reflektor" proudly on the glass, publish the [real] specs and allow the marketplace to decide. After all, JJ seems to be doing pretty well with that business model.

Why do that when you can give them cool names like "Mullard" and "Tung Sol" ?:rolleyes: Bob

[mark norwine]

Why do that when you can give them cool names like "Mullard" and "Tung Sol" ?:rolleyes: Bob

Here's why: Honor. Class. Dignity.

The current-production tubes being sold today as Mullard and Tung-Sol, etc. are quite simply *not* Mullards or Tung-Sols.

Good heavens....the man stencils "SVETLANA" on tubes that were *not* *made* *by* "Svetlana" (aka Winged C).

[III]

To rehash my earlier post (#35)...

Is the RI Mullard actually the same internally as the LPS?
Do any New Sensor tubes hold up in Cathode Follower stages?
Here's why: Honor. Class. Dignity.

The current-production tubes being sold today as Mullard and Tung-Sol, etc. are quite simply *not* Mullards or Tung-Sols.

Good heavens....the man stencils "SVETLANA" on tubes that were *not* *made* *by* "Svetlana" (aka Winged C).
Although I don't disagree... I'm pretty sure 99% of tube buyers who know about original Mullards etc, know the New Sensor rebrands aren't anything like the originals.

I like my real SED's and limited supply of NOS tubes but retubing all my amps with NOS that's worth more than what I paid for the amps themselves is kinda ridiculous for a working stiff like me.

[rockon1]

Here's why: Honor. Class. Dignity.

The current-production tubes being sold today as Mullard and Tung-Sol, etc. are quite simply *not* Mullards or Tung-Sols.

.

Mine was a totally rhetorical statement. I have pretty much disdain for NS's use of such distinguished venerable names.

To rehash my earlier post (#35)...


Although I don't disagree... I'm pretty sure 99% of tube buyers who know about original Mullards etc, know the New Sensor rebrands aren't anything like the originals.



I dont believe thats true unfortunately. Ive read all too often statements like "are these comparable in tone to the originals" or "are these made the same way as the originals" etc. Bob

[rockon1]

Heres a real Tung Sol! Bob

http://i41.tinypic.com/24nflo6.jpg

[croto5000]

this thread intrigues me quite a bit. i picked up a used carvin mts last year just for messing around. none of the tubes in the power section matched so i decided i'd buy some new preamp tubies while i was replacing the 5881s. i found a great deal on some EH 12AX7s and i liked their sound but before long, my high gain channel was only able to produce clean sounds, even with the drive knob cranked. i thought 'no problem, just needs to be swapped with a different one. par for the course'. wrong. all 5 of the EH tubes i got ended up getting killed in that thing. at first i thought my amp was devouring them but the sovtek 12AX7WA's that came with it still produced plenty of overdrive. not the kind of overdrive i like but they did a better job than the junk i replaced them with.

anyway, tubedepot had some good prices on several 12AX7s so i got 2 of like four different brands. Tung-Sol RI, Sovtek 12AX7WB, Sovtek LPS. i forget the last one, may have been one AT7 for my reverb driver. anyway, skip ahead 2 months later - tung sols are dead, lps are dead, and the 12AX7WB's still seem to work fine!

the odd thing is though, when i say dead it only means they take my overdrive channel from a roaring beast down to a meowing kitty. they work fine in the PI position (though i wouldn't trust them in there for the long term) and produce normal volume levels when used for the clean channel of the amp.

now, i haven't ruled out the amp entirely as there's still like 4 other things wrong with it. but since you have all had issues with the exact same tubes i think i'll let my amp out of the doghouse for now.........

[III]

I've got a few Tung Sol RIs that I've been using awhile. Some from a tube dealer and some from Musicians Friend. Both sets sound sound very similar, and aren't noisy. Maybe I'm just lucky.

I like 'em in my Bassman and 5W Blackheart.
I dont believe thats true unfortunately. Ive read all too often statements like "are these comparable in tone to the originals" or "are these made the same way as the originals" etc. Bob
That's cool... as one of TGP's tube guys, I'm sure you've followed tube threads way more than me.

Do you know which NOS tubes are known to hold up best and sound decent in Cathode Follower positions... such as V2 of my Super Lead? Recently I seen Telefunkens recommended soundwise for V2... do they hold up well?

[dazco]

bought 2, 1 was bad. Found i much prefer my stash of 1st gen Chinese anyways...

[aarondavis]

I found the Tube Depot online. Is that a good place to buy? I thought about getting at least one NOS 12ax7 for my V1. As for my regular 12ax7s and my EL84 output tubes, I think I'm just going to go with JJs. After reading all kinds of threads and searching the web, it seems that JJ's are still the best new production tubes available.

[rockon1]

I've got a few Tung Sol RIs that I've been using awhile. Some from a tube dealer and some from Musicians Friend. Both sets sound sound very similar, and aren't noisy. Maybe I'm just lucky.

I like 'em in my Bassman and 5W Blackheart.

That's cool... as one of TGP's tube guys, I'm sure you've followed tube threads way more than me.

Do you know which NOS tubes are known to hold up best and sound decent in Cathode Follower positions... such as V2 of my Super Lead? Recently I seen Telefunkens recommended soundwise for V2... do they hold up well?

To be honest Im not sure where and if my amps have cathode follower positions. I imagine they do though. I cant remember the last time I had an old stock pre fail-except microphonically. A lot of old long plates just dont like the combo amp evironment. Bob

[go7]

Well, that's where the problem is.

These companies are inconsistent at best. At any given moment, a great batch of brand X could arrive and people will be glowing how great they are.
2 months later, a batch of rejects arrive and guys post their negative experiences.
Currently there is simply no " Best Brand" They have all produced Cherries and Lemons and continue to do so.

The same questions are asked on other forums as well, and basically the same reply's and experiences are posted there as well.
Myles 111 posted detailed spec sheets on new production 12ax7`s. Trout said it all. Basically new production is so inconsistant it`s hard to draw any conclusions.

[sidehatch]

I have tung sold in most my amps and have never had a problem. I got them from a local shop untested too. EH sounds good but I ave had way tool may fail on the gig(starts humming) GT's mullard sounds great but are unreliable. JJ's dont sound great to me but work fine. Chinese's sound ok but always work as do the 12ax7wa's and wb's.

For tone its the Tung sol,EH and mullard. I do have a lot of anos RCA's that I use it the choice positions.

[Prairie Dawg]

"Tung-Sol" my ass.

IMO, if Mike Mathews is proud of the products he produces at his Reflektor factory, he should proudly print the name "Reflektor" on the products.

Buying the rights to a name, then printing that name on a product that bears zero resemblance...pretty shameful, if you ask me

(which, I realize, you didn't!)

I've been saying that for years Mark. It's not just New Sensor either. Let me elaborate.

Years ago, all the domestic tube makers (RCA, Sylvania, Hytron, Raytheon, GE, et cetera) qualified their devices to RETMA (now EIA) standards. That is, a given device was constructed to a certain standard and exhibited certain characteristics. That is why a 12AX7 from any one of them exhibited the same characteristics and performance as the next. In fact the tube makers recognized this by often buying and relabeling other people's product to make up an order.

I expect the western Europeans did about the same thing.

We don't have that any more, and the people who are making tubes probably never qualified their devices to RETMA standards. Instead, all you really know about a tube from, say, the Guangdong People's Tube Factory in North Korea is that if fits in the hole and sort of works.

Today, we have little but anecdotal stuff: "Those Guangdongs is da bomb. It will rock your world."

Sheesh.

I'm in mind of a large batch of tubes that came from one of the offshore makers whose tube pins were .010 undersize. In inverted service they had a ridiculous habit of dropping out of the socket. That should never have left the factory and wouldn't have, in the days when there were standards.

The information wasn't unknown, either. It's all in MIL-DTL-12883-1/F and similar sources.

The answer was "scrowge your tube sockets, booger up the pins and make it work.

Things are getting better-there is more published information about tubes from the old Combloc these days, but the out of the box reliability is still not at a comfortable level.

Nice to see ya Mark. I wondered where you'r been.
:bow

[Kage]

this thread intrigues me quite a bit. i picked up a used carvin mts last year just for messing around. none of the tubes in the power section matched so i decided i'd buy some new preamp tubies while i was replacing the 5881s. i found a great deal on some EH 12AX7s and i liked their sound but before long, my high gain channel was only able to produce clean sounds, even with the drive knob cranked. i thought 'no problem, just needs to be swapped with a different one. par for the course'. wrong. all 5 of the EH tubes i got ended up getting killed in that thing. at first i thought my amp was devouring them but the sovtek 12AX7WA's that came with it still produced plenty of overdrive. not the kind of overdrive i like but they did a better job than the junk i replaced them with.

anyway, tubedepot had some good prices on several 12AX7s so i got 2 of like four different brands. Tung-Sol RI, Sovtek 12AX7WB, Sovtek LPS. i forget the last one, may have been one AT7 for my reverb driver. anyway, skip ahead 2 months later - tung sols are dead, lps are dead, and the 12AX7WB's still seem to work fine!

the odd thing is though, when i say dead it only means they take my overdrive channel from a roaring beast down to a meowing kitty. they work fine in the PI position (though i wouldn't trust them in there for the long term) and produce normal volume levels when used for the clean channel of the amp.

now, i haven't ruled out the amp entirely as there's still like 4 other things wrong with it. but since you have all had issues with the exact same tubes i think i'll let my amp out of the doghouse for now.........
I have an MTS too and was experiencing something similar, where it seemed like the amp was just eating my preamp tubes that stopped after it was serviced. So it may be something with the amp.

[croto5000]

I have an MTS too and was experiencing something similar, where it seemed like the amp was just eating my preamp tubes that stopped after it was serviced. So it may be something with the amp.

oh yeah? what exactly did you have done when it was serviced? i'm about ready to leave this thing out by the curb lol

[Kage]

Honestly, I'm not sure. I'd bought it used at GC recently enough the they had me take it to their tech who had it for a couple of weeks and told me he couldn't find anything seriously wrong with it. He apparently told the guys at GC that he fixed a few minor things but I never got the full scoop. Works fine now and I had it switched over to EL34's. Any decent tech should be able to look it over and see if there's something wrong with it.