JAN GE vs JAN Phillips 12AX7WA's

[ShamefulAddiction]

Is there any difference in these tubes other than the GE's having more gain on tap? The Phillips have the longer plates, so is that going to make them more prone to microphonic failure? After all, they're JAN. They should be virtually bullet proof.

 

[Timbre Wolf]

The "JAN" designation isn't a get out of jail free card, fer kripes sake! :lol: The physical properties of longer plates makes them generally more prone to microphonics than shorter plate tubes.

The two tubes do have different character. I would not ascribe higher gain to the GE, though. I actually find the Philips (ECG) to have a bit more breakup. Both tubes have solid, punchy lows, but I find the GE to be quite a bit more bland. So much so, in fact, that it threw me off the trail of GE tubes for quite some time, until I "discovered" early GE and Ken-Rad tubes - but that is a different story (about much more interesting tubes).

The mids of the JAN Philips ECG 12AX7WA break up in a very interesting manner. Coupled with its zingy highs (which mellow a bit over time), this tube lends itself well to power chords galore. Give me a LP Junior and an amp loaded with this tube in V1, and I'll pound out rockin' riffage all night.

The GE 12AX7WA... ennh; not so much. Just my opinion - anyone else want to pitch in and compare the two?

- Thom

 

[212Mavguy]

Hi,

I think that the GE would work well as a PI tube if you have one balanced between both sections, and it has some nice smooth cleans. I'd use it in V1 in a fairly powerful Fendery clean tone type of amp. Bet an archtop Jazzbox would sound great through it. I agree with the posted sonic impressions of both tubes.

I think that the Sylvania long grayplate design is more prone to microphonics over time, especially with lots of on/off cycles. The military ones have more robust looking micas, that should help with that problem. When slightly overdriven, it sounds a bit Mullard-ish, very fat, but when pushed heavily into overdrive it has a grittiness that the more creamy sounding short plate Mullard lacks.

My preference in Sylvania grayplates is more towards the rarer short grayplate military 12ax7, fatter mids in that one, less bottom, more resistant to microphonics in the couple I have. Would be decent in a Mark 1 lead channel first position for early Santana-esque sounds.

As a side note, I have noticed that the Sylvania long grayplate tend to have consistently more gain when new or lightly used than just about any 12ax7 out there. It would work well in a drop tuning chugga chugga smack yer chest thang. My personal fave version of the Syl long grayplate is the yellow print 12ax7/ecc83/7025 labeled one. Peace.

 

[Timbre Wolf]

My preference in Sylvania grayplates is more towards the rarer short grayplate military 12ax7, fatter mids in that one, less bottom, more resistant to microphonics in the couple I have. Would be decent in a Mark 1 lead channel first position for early Santana-esque sounds.

Those are the square-getter ones, made in '57 - yes? If so, they're a superb tube. Another poster on The Gear Page and I dubbed those the "better RFT" because they've got similar breakup, but retain better clarity.

Question: are you equating the earlier-production long-plate Sylvania 12AX7A with the later JAN Philips ECG 12AX7WA? I know the later tubes were made in Sylvania facilities, and they have the same plate structure, but I don't think they sound quite the same.

- T

 

[212Mavguy]

They may not sound exactly the same, but there is a family tonal character, like the Raytheon blackplate 12ax7 rectangular getter, 5751 blackplate windmill getter, and the triple mica 12at7 red print exhibit. Those tubes have a strong family tonal resemblance for sure, even though they have different designations.

Another example of what I call family tonal character is the Philips shortplate 12ax7's from Miniwatt, Amperex, Philips, Mullard and Siemens. Although they exhibit similar appearing structures, they have a family resemblance in tone while retaining their individual brand tonal quirks as well.

 

[ShamefulAddiction]

Well what I'm trying to find out is which (the GE or the Philips) would be best suited for what I want. And that is a tube that is going to resist microphonics for a good while (it's going in a 2x12" combo so hello vibration) and give me smooth tone without cutting my top end or choking the gain. I'm leaning more towards the GE on this one simply b/c of the shorter plates used.

Edit: I think I found what I was looking for in the Sylvania 12AX7WA

 

[Timbre Wolf]

Another example of what I call family tonal character is the Philips shortplate 12ax7's from Miniwatt, Amperex, Philips, Mullard and Siemens. Although they exhibit similar appearing structures, they have a family resemblance in tone while retaining their individual brand tonal quirks as well.

I agree - they're all laden with rich harmonic overtone type distortion, whereas others with similar-looking design (such as RCA 12AX7A) maintain more distinct fundamental tones. Ironically, from an electrical engineering point of view, the Philips tubes would be much less desirable, because any distortion (musical or not) is unwanted.

Back to the original question: GE may be a better pick because of the short-plate/less microphonic correlation. But, of the two, I would recommend the Philips ECG because of the performance. Overall, I would recommend trying some other choices - like from the Raytheon "family" that Mavguy mentioned.

- T