Are all current production tubes mediocre?

[George61]

I built a Ceriatone EF86 36W and I put current production JJ 12AX7's and EL84's in it. It didn't have very much time on it, 200 hours at the absolute most, and the amp suddenly became very noisy; both hum and hiss. It was the phase inverter tube. I put in 12AX7's out of my Mesa Boogie which are so old they are no longer clear, they are brown from the baked on dirt. I have been using tube amps since the 60's and I have never had a tube fail so quickly. In fact, I don't remember replacing pre-amp tubes except for V1 in my Boogie because it became microphonic.

I would like to try NOS pre-amp tubes in the TMB channel but I am not willing to spend a lot of money on them. $50 each max. What I have found, that might be OK, are pre-war Ei 12AX7's. All the dealer has are listed as testing as high-gain. Is that good, bad, or indifferent?

I also found RCA 12AX7's. The dealer has short plate and long plate. I would imagine short plate would be the choice?

Solder on,
George

[billyz]

I have been very pleased with most recent Tungsol ri tubes. I have been using the 12ax7, 6l6gc, and el34b's , so cannot speak for the others. I have had good results with Sovtek 5ar4 as well.

[Reeltarded]

There are no bad tubes, just great times for bad stuff to happen to good people.

Shine. It's your time.

(and yes, all new tubes suck because Chinese children can't read a micrometer for setup)

[David Root]

The Tungsolskis (ie reissues) I have tried, 12AX7, 6L6GC-STR short bottles, are OK although the 6L6s have a rather rough high end to my ears, certainly compared with even a well used '60s RCA blackplate. The 12AX7s I think are a bit better but old Amperex or Mullards they ain't.

The prewar EI 12AX7s are good, they were built on basically Telefunken equipment and sound very similar. Very good in first stage and phase inverter. High gain is good so long as it's smooth, which these are. Spikey is not good. Make sure they are in fact prewar, otherwise you're paying too much as the quality went into the old toilette later on..

RCA short gray plates are the standard workhorse 12AX7 that BF Fenders shipped with. For a bit more harmonics, more like an Amperex or similar Euro tube, the long plates are better, especially the '50s RCA blackplates. Use long plate in the first stage and the phase inverter positions for optimum tone.

[yalesmith]

for some reason they all stink except for tungsol and winged C. the tungsol 12ax7 are really really good as well as the 6v6's, I have not tried anything else. The winged c el34 and the the 6l6's are superb. I compared the tungsols to a bunch of vintage 12ax7 and they compare nicely.

[gary sanders]

(and yes, all new tubes suck because Chinese children can't read a micrometer for setup)

Thats so true its freakin hilarious !!!!

[txbluesboy]

I got a few sets of Winged C 6L6GC-WC's to try. The first set I tried drifted so far after about 20 hours of use that I wouldn't even call them a matched pair anymore. Was this a fluke or has anyone else noticed this

[Structo]

It really depends where you buy them from.

I bought a quad of TAD 6L6GC STR's from a dealer and by the end of the first week of operation they had drifted close to 10-12ma apart.
My 100w ODS amp has two bias pots so I can balance the two sides as close as I want but I was unable to get these very close, even with swapping them around.

Then I bought a quad of the same tube from Doug's.
After running them for a while one had drifted 3ma, perfectly acceptable to me.
I think burning in the tubes before matching is necessary with today's production tubes.
So read the fine print when you order and make sure that they do indeed burn them in.

I really liked the Winged C 6L6 in my 50w ODS but when they nearly doubled in price I couldn't afford a quad of those.

So in the 100w amp I have tried the Tung Sol 6L6 STR, JJ 6L6 and the TAD 6L6GC STR

[George61]

Thanks for the replies. I ordered Tung-Sol 12AX7's from the TubeDepot. I have a Tung-Sol in the EF86 channel of this amp and I like it. In fact, I don't know why I'm so worried about the 12AX7 tubes as I like the EF86 channel better than the TMB channel anyway. I also order a bunch of tube boxes so I can store my ever expanding collection of NFG tubes.

The Mesa tubes are definately better than the JJ's and they appear to be Shuguang tubes. They are from approximately 1990. They must have been made by an exceptionally bright kid who could read mics.

As far as power tubes go, I have no-name brand Russian 6P14P-EB tubes and JJ EL84 tubes and I like the JJ's.

[Reeltarded]

Ahh.. you got tubes made by that one kid.. a legend.

His name is Chu Shwang Li Ir, but his friends call him Mike.

[tubeswell]

As far as modern production tubes go, I like the JJ6V6S - all the ones I've gotten so far (that about 40 or so over the last few years for different amps) have proved to be reliable. I don't like their 6L6GC however.

I generally find Sovteks reliable and likeable, but had a couple of bad experiences with recent batches of EL84s.

I find most modern pre-amp tubes (12AX7s) (of various 'brands') produced in New Sensor's factory don't handle high (like 100 or so) h-k voltages at all. That is very frustrating.

[tubeswell]

As far as power tubes go, I have no-name brand Russian 6P14P-EB tubes ...

FWIW, these are not 'no-name'. These are the Russian 'EL84M's and will typically give faithful and reliable burn times lasting for 1000s of hours.

[harleyboy2112]

I got a few sets of Winged C 6L6GC-WC's to try. The first set I tried drifted so far after about 20 hours of use that I wouldn't even call them a matched pair anymore. Was this a fluke or has anyone else noticed this

I've noticed it on numerous pairs.
I've retubed some amps for friends and myself after they started sounding out of sorts. I saved the tubes and recently got a tube tester.
The tubes all test good but the "matched pairs" were way out of whack.
I mangaged to get a matched pair out of the used ones I have laying around but haven't had a chance to try them yet.

[BTF]

I had some unused JJ ECC803s from their early first batches. I recently put one in my Presonus AcoustiQ preamp. It began malfunctioning after about 2 hours of use. I had another act up in my Twin a while back. Until then I had thought JJ ECC83 tubes to be bulletproof. However, this set WAS from early runs. I'm just glad the tube didn't cause any damage to the Presonus since I'd need a microscope to repair anything in that...

It always irked me that online reviewers derided EI tubes so mercilessly. I often wonder how much of that anti-EI vibe aided in their downfall. I have about a dozen of the silver-plate ECC83s and they are wonderful- quiet and VERY gainy. I did have some of the grey-plates that went microphonic, but overall I had excellent luck with them. They seem to have a better average with me than the JJs I've got.

[brentm]

It always irked me that online reviewers derided EI tubes so mercilessly. I often wonder how much of that anti-EI vibe aided in their downfall. I have about a dozen of the silver-plate ECC83s and they are wonderful- quiet and VERY gainy. I did have some of the grey-plates that went microphonic, but overall I had excellent luck with them. They seem to have a better average with me than the JJs I've got.

I've not found a current production tube that I would want to repurchase, except screened (e.g. TAD or Ruby) Chinese Shuguang tubes.

Having said that... The Ei tubes are the best dollar-for-dollar value at the moment, in my opinion. I picked up 10 of them from AES and have been extremely happy. I've tested half of them in my amps and have not had a single microphonic tube yet. I did have one of their yellow box ribbed plate tubes go microphonic some years back...

I agree, it's a shame that Ei no longer produces tubes. They are some of the best sounding tubes I've found at that price point.