JJ 12ax7 versus RFT 12ax7

[dogears]

Back when I first started messing with tubes, I frequently used JJ 12ax7 tubes. They are not very bright and had a smooth mid.

Now that I have my Bludotone with them, I decided to retube V1 and V2 of my Glaswerks with the JJs as a test. This is HRM. No snubbers and choke on.

Clip 1 - V1 RCA long plate, V2 RFT http://www.scottlernermusic.com/2008/FatRFTWerks57.mp3

Clip 2 - V1 and V2 both JJ 12ax7. I did not bother trying others. I just grabbed two randomly. http://www.scottlernermusic.com/2008/FatJJWerks57.mp3

Same exact settings and mic between clips. I just put the amp in standby and retubed.

What do you think??

Thanks!

[Fischerman]

Snuck a low vol listen at work and it sounds like the JJ clip has a little more gain. As far as the tone...each clip has qualities that I like but it's difficult until I get a better listen. The JJ sounded fatter...RFT more clarity.

[stelligan]

For me - they are both articulate, but with a different characteristic. I hear a tad more high end brashness after the attack on the first clip - some more high end "hair". The JJs seem to not have that hair at the attack, but a nice little thump instead. Kind of "rubbery"? I like both. The RCA/RFT clip is just a bit more "aggressive".

And have I mentioned - you play well.......

[heisthl]

They're both great but #1 sounds fatter to me and on first impression would be my choice.

[dave g]

I actually did this exact same test as well last night in a 50 watt non-HRM. I did a little shootout between Tung Sol reissues, JJs, EHs, Rubys, and some NOS GE and Telefunkens. I too noticed that the JJs were the darkest of the bunch - not to my liking at all. My favorite characteristic of the D-tone is the clear and airy high end you can get, and I just felt like that was completely lacking in the JJs. Believe it or not, the EH 12AX7s were my favorite of the bunch, even over the NOS stuff. Totally fat but with a really articulate top. Then again, every amp is different and it could just be that mine likes the EH tubes.

[ampdork]

I thought the first one sounded articulate and bright ina good way. The second seemed to have a low mid content that was there but sounded a little smudgy, gave it a somewhat smoother vibe but lacked a good definition in that area. Maybe a little hint of that on top of the first would be neat but all in all I think the first sounded best. Difficult not to get lost in the chops though. I said it before and will say it again your groove sounds totally new again. Sick!
I switched back every few bars. Still had to do it twice to get back to tone critique. Wicked lines...

['67_Plexi]

From my recent experience with JJ's I found they had little to no microphonics issues, but had a much higher level of filament noise compared with a good Chinese tube. Tonally I found them a little one dimensional to.
They generally have higher gain and a lower current draw, that could be a good or a bad thing depending on what you are looking for.

Again, just a personal experience, not a given.

[dogears]

Here is another RFT clip from this morning. I changed a bunch of other stuff too.

http://www.scottlernermusic.com/2008/FatRFTWerks330.mp3

[ayan]

Back when I first started messing with tubes, I frequently used JJ 12ax7 tubes. They are not very bright and had a smooth mid.

My experiences with the JJ A12AX7s are that they are good tubes in terms of being non microphonic and consistent in their performance. Alas, consistently rather toneless as well... They have a fairly tight bass response and a hard (not harsh, but stiff) top end, with little or no harmonics.

I test tubes with much lower gain settings than your clip and nothing in the loop. Plug a tube in and play a couple of chords on different parts of the neck and listen for harmonics. Of course, harmonics will be generated by a number of differnet things in a tube: gain, high end content and whether the tube is matched or not. Still, for the V1 and V2 positions (also test with very low gain in OD mode), the same tubes consistently score the highest in terms of "musicality."

Out of my JJs stock, about 50% of them are what I consider to be tone dead. The other half is OK, but not quite as musical as some NOS GEs I have and one (a single one, sadly) Ei form their golde age. EHs are just one click above being tone dead, and the Sovtek LPS are below tone dead in my no so humble opinion. Playing any one of my amps in clean mode, if I plug the Ei (higher gain) instead of a JJ, I will hear harmonics gallore, and the GEs will be simlarly rich. The JJs will not do that nearly as much.

Word is out that the Chinese 12AX7Bs are the best sounding tube out there for other than high gain applications, so I will get me a batch of those soon and go through a few. For high gain stuff, the JJs are probably a good choice because they nuke some of the high end and they are not microphonic at all.

Cheers,

Gil

['67_Plexi]

Back when I first started messing with tubes, I frequently used JJ 12ax7 tubes. They are not very bright and had a smooth mid.

Word is out that the Chinese 12AX7Bs are the best sounding tube out there for other than high gain applications, so I will get me a batch of those soon and go through a few. For high gain stuff, the JJs are probably a good choice because they nuke some of the high end and they are not microphonic at all.

Cheers,

Gil

110% agree. About 10-15% are unuseable due to microphonics or the triodes are just so far out from each other.
Definately the best sounding and most reliable.....and as an added bonus probably the cheapest on the market if you buy them white box / bulk.
About 15 to 20% are fine for higher gain, certainly used a few of them in stages much higher than anything in a Dumble without any issues.
Combos may have more issues however.

The JJ filament noise really spoils them for me. They never used to do that a couple of years ago.

I just used the last of my Ei's a while back. 95% of those would fail on microphonics in any position but the PI, but if you got a gem they were as good as virtually any good NOS tube. Dirt cheap too at the time.
I never found the golds to be any better than the silvers, just more expensive and prettier looking.

[ayan]

I just used the last of my Ei's a while back. 95% of those would fail on microphonics in any position but the PI, but if you got a gem they were as good as virtually any good NOS tube. Dirt cheap too at the time.

Yep, I have one left. I just checked and CE Dist. has them in stock, but at $13 a piece, and considering the percentageo of michrophonics in the past, not a vey good option I'm afraid.

Gil

[G-Dorian]

The JJ's by a long shot. Much smoother . .

[greiswig]

I haven't had very good luck with JJ's. The standard ECC83 I find to be hard and lifeless for the most part, although I did stumble on one that sounded great in the distortion section of my Bad Cat.

I got a long-plate JJ 803S that I put in V1 in my Bad Cat amp, and it sounded just great! Based on that, I got another one to try out in my D'Lite. Didn't sound good at all in there. I swapped that tube for the one from my Bad Cat, and that first one sounded great in the D'Lite, too.

Methinks they have inconsistent quality.