VetPsychWars
Active Member
JAN-12AX7WA or JAN-21AX7WC. 6057 if you can find and afford them.
For mid-priced tubes, I like US NOS brands like RCA, Sylvania, GE, etc. (nobody has mentioned GE -- is there something I missed?)
I know people rave about the Sovtek LPS tubes, but I have some concerns about other Sovtek 12AX7s I've used.
A long time ago (15-20 years) I had gear with Sovtek tubes (more than one piece, IIRC) and the emissivity dropped off significantly after a year or two of operation. My guess is that their cathodes became poisoned, but I don't have any confirmation or data. Maybe Sovtek or New Sensor addressed this problem since . . . I'd be interested if others pull and check Sovteks that have been in service for a a while and see if they get comparable results.
I bought a few of the LPS variety from Jim and wanted to use them in the phono stage of a Scott receiver, with some other brand in the tone and line stages. Bad idea, as the filaments were quite different from the other tubes and the voltages across each tube (in the DC serial string supply) were way out of spec.
I know people rave about the Sovtek LPS tubes, but I have some concerns about other Sovtek 12AX7s I've used.
A long time ago (15-20 years) I had gear with Sovtek tubes (more than one piece, IIRC) and the emissivity dropped off significantly after a year or two of operation. My guess is that their cathodes became poisoned, but I don't have any confirmation or data. Maybe Sovtek or New Sensor addressed this problem since . . . I'd be interested if others pull and check Sovteks that have been in service for a a while and see if they get comparable results.
I bought a few of the LPS variety from Jim and wanted to use them in the phono stage of a Scott receiver, with some other brand in the tone and line stages. Bad idea, as the filaments were quite different from the other tubes and the voltages across each tube (in the DC serial string supply) were way out of spec.
So they draw different current than other 12AX7? Higher or lower?That’s terrible. I have to re-check in my Fisher 400. They are on the same string I believe with Matsushita tubes in the preamp.
Sorry, I don't recall whether they were higher or lower, but I wasn't expecting so significant a difference.
I'd second the 7025 old manufacture tubes. A low noise version of the 12AX7 supposedly designed for applications like phono stages. It's what I've settled on after trying Telefunkens, Mullard 10Ms, 5751s, etc, etc...
Got to agree on JJ's. I have had excellent results with their ECC83S/12AX7-S. This tube resembles the 6DJ8's construction (frame grid style?). They last a long time and my experience is that they don't become microphonic like many other newly manufactured 12AX7A's. And, they are relatively cheap at around $12.95 from many suppliers (Like AES in AZ). I haven't tried the JJ E88CC which looks similar at double the price.
JJ ECC83S has a conventional grid in a "box plate". E83CC has a frame grid in a similar plate.
By the frame grid the tubes seem to have less spread in parameters, i guess there is no
need for "matching" or what vendors might call it.
arts
Addicted Member
The JJ ECC83S is an excellent tube. Very quiet and has extremely low hum in AC heater applications. This is a great tube where low-microphonics are essential. They do well in musical instrument amps, especially combos, and can endure the abuse long term.
The JJ ECC803S has become my go-to long plate 12AX7 choice. Again, a very quiet and low-noise tube, also with low microphonics. They can't survive in high vibration environments though, due to the large plate structure, and will soon turn into baby rattles in a combo amp.
In my experience, regular off the shelf JJ stock has yielded a majority of tubes with very closely matched sections. This clearly shows quality and consistency in the manufacturing processes.
The Sovtek 12AX7LPS has become a bit of a disappointment. I liked them when they first came out, and used them for quite a while, but the thrill is gone. In service failures have become an issue, and receiving outright duds is all too common. In addition, the (usually) wildly mis-matched sections are laughable.
The JJ ECC803S has become my go-to long plate 12AX7 choice. Again, a very quiet and low-noise tube, also with low microphonics. They can't survive in high vibration environments though, due to the large plate structure, and will soon turn into baby rattles in a combo amp.
In my experience, regular off the shelf JJ stock has yielded a majority of tubes with very closely matched sections. This clearly shows quality and consistency in the manufacturing processes.
The Sovtek 12AX7LPS has become a bit of a disappointment. I liked them when they first came out, and used them for quite a while, but the thrill is gone. In service failures have become an issue, and receiving outright duds is all too common. In addition, the (usually) wildly mis-matched sections are laughable.
After noticing some noise from my EAR clone phono stage and/or PAS used as a line stage, I began rolling tubes. I’ve got a pretty good selection of vintage tubes: everything but Mullards.
What tubes are in now? Sovtek 12ax7LPS. They are very quiet and I’m happy with the way things sound. Will see how they hold up.
What tubes are in now? Sovtek 12ax7LPS. They are very quiet and I’m happy with the way things sound. Will see how they hold up.
LP-THORN
Super Member
New term = ANOS. "Almost..."
Reopening a Zombie Thread for a bit of newer info than 2022:
I recently bought a Pro-Ject Tube Box DS2 phono preamp that came with mystery ECC83/12AX7 tubes, I could not tell what they were as they were covered by some EAT aluminum finned "coolers" that actually don't do much cooling (if any) they do more to help dampen the tube to prevent microphonics. Convention wisdom is that Pro-Ject used either modern Tong-Sol or JJ tubes, but when I finally got the cooler off one of the tubes it turned out to be a Psvane ECC83. It was not bad at all, but the sound stage was a bit 2 dimensional, confined to behind the front of the speakers. Several reviews of this tube said it was a bit microphonic, maybe that is the reason for the cooler/dampers ???
I rolled in a set of GE-JAN's( 5751 not the 7025) to see what difference there was but they got very bright/brittle after 3-4 hours, so back in with the Psvane (the 5751s will be spares for my guitar amp). I did a lot of internet sleuthing and determined that a set of JJ E83CC frame grid tubes might be worth a try.
Yowza! These JJ E83CC tubes have strong tight bass (SLAM?) excellent mid range where the voices are crystal clear, and sweet but not rolled off highs. Best part is that the sound stage is now wide, deep, and high and 3D- It now sounds like performers are in the center of my room.
I recently bought a Pro-Ject Tube Box DS2 phono preamp that came with mystery ECC83/12AX7 tubes, I could not tell what they were as they were covered by some EAT aluminum finned "coolers" that actually don't do much cooling (if any) they do more to help dampen the tube to prevent microphonics. Convention wisdom is that Pro-Ject used either modern Tong-Sol or JJ tubes, but when I finally got the cooler off one of the tubes it turned out to be a Psvane ECC83. It was not bad at all, but the sound stage was a bit 2 dimensional, confined to behind the front of the speakers. Several reviews of this tube said it was a bit microphonic, maybe that is the reason for the cooler/dampers ???
I rolled in a set of GE-JAN's( 5751 not the 7025) to see what difference there was but they got very bright/brittle after 3-4 hours, so back in with the Psvane (the 5751s will be spares for my guitar amp). I did a lot of internet sleuthing and determined that a set of JJ E83CC frame grid tubes might be worth a try.
Yowza! These JJ E83CC tubes have strong tight bass (SLAM?) excellent mid range where the voices are crystal clear, and sweet but not rolled off highs. Best part is that the sound stage is now wide, deep, and high and 3D- It now sounds like performers are in the center of my room.
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Wait! These were GE 7025? Not 5751?
my bad, they were the 5751- I fixed the first post (soo many numbers for pretty much the same tube )
