Opinions on Current Production Valves for the Express

[Littlewyan]

I'm looking at swapping out my 6V6s in my Express for EL34s, I want a bit more headroom and also feel the 6V6s are too....full sounding for this amp? Also I think the EH6V6s I've got are struggling with my 430V B+. I put my Winged C EL34s in there shortly for testing something else and definitely noticed a difference, however those valves have a terrible buzzy low end, I think they are duffers.

Anyway I'm leaning towards JJs as their 12AX7s have been fantastic for me, but they do a EL34 or a E34L. Anyone used both to compare? I know M Fowler likes JJs so hopefully he'll see this.

[M Fowler]

I've been using the EL34L which have higher grid voltage rating then the EL34 biased with more negative grid voltage and allows more headroom per what CED states on their website and I have good tone and apparently good luck.

I have had problems with JJ GZ34 tubes but that may have been my recklessness.

[rooster]

I like the KT77 from JJ, another EL34 spin.

And Mark, you may not know this but JJ had a large run of faulty GZ34s. If you were buying them from a supplier who was just selling tubes, then you bought some. Eurotubes was getting bad feedback from their customers at the time - this was going on about 3-4, maybe 5 years ago now? - and they started plugging them into an amp-like-real world tester they made before selling them, trying to head off the problem. I ran into three bad ones in a new build at the time and it totally freaked me out. As far as I know, none of the other large sellers had any idea this was going on. It's even possible there are some sitting on shelves somewhere right now. Crazy.

Btw, the maddening thing about the faulty tube was that it might work five times in a row, as you turned on the amp, but then not work on the six try.... And then work on the #7. Also, when it failed, there was some purple sparking going on inside the tube near the pin base. Finally it just wouldn't turn on.

Oh, and everything was finally corrected going back at
least 2 1/2 years ago, maybe longer. I think it was actually Eurotubes who pointed out the problem to JJ. Yeah, some companies actually listen to their customer's feedback.

[rooster]

To the OP, in regards to 12AX7s, I would suggest that you acquire some classic older American and Euro tubes that you know are working correctly, volume and noise-wise, learn how they impact the tone of the amp and your guitar, and then buy some new contemporary tubes to compare side by side... Trust me, it is worthless drivel to read about how a tube is supposed to sound - you need to hear it for yourself. Make the effort.

I have a Champ amp that I use as my initial test bed for this, basically volume and noise, and then if they pass this test, it's off the the Express. The Express V1 is the ultimate physical vibration tester, but remember that the tube that fails here may be fine in a SR V1 position.

One thing regarding noisy tubes in the Champ? If they aren't quiet in the Champ, I have to toss them. Also, it is incredible how much crap is being sold on ebay, so beware as you search out those classics.

[Littlewyan]

Yer see I'm not a NOS guy, I don't see the point when a) current production is the future b) what you get now are basically what the guys years ago who first sieved through all old stock called duffs c) Even if I bought them and liked them, I may not be able to get the same valve again or same tone from a different valve.

I do agree with you though I do have to try different valves myself. Atm I have some JJs, EH, Sovteks and a Tung Sol reissue. The EH and Sovteks are the worst, but I got them from the same supplier, maybe I got sent the rejects. The JJ valves have become my comparison valves. For instance yday I thought the amp had piercing treble, swapped the EH V2 for a JJ, problem solved.

Now as for the EL34s i'm stuck between the JJ EL34 and JJ E34L. So I'm going to stick my current EL34s in from my Marshall to see what the headrooms like. Atm I pretty much have no headroom, starts overdriving on 1 on the volume!

[Synchu]

Couple of notes, albeit I am doing the tube rolling in the last couple of weeks in an Asteroid/K60 build, that is obviously different from an Express:
- JJ EL34 - I had an old set (used not more than 15 hours in a Diezel amp) lying around. They are probably 5-6 years old production, so might not be comparable to the current production ones, but 2 out of the quad gone bad after just couple of days on the Asteroid voltages.
- Ruby EL34BHT (EDIT: it is TAD EL34 BHT) - good tube, doesn't sound as good as JJs but much more reliable (I am using this for years in Marshall and Diezel amps). Used it for week or so in this one - no problems.
- Russian 6p3s-ev (sort of 5881 equivalent) - although they got hit with twice the voltage as per the datasheet they run good (I am using them in few other builds at nearly 500V plate voltage as well - no problems). Just don't sound good in this one:)
- EH 6CA7, I got those in couple of days ago - Best sounding in this build - gotta play few weeks more before say something on the reliability

I don't seem to like JJ preamp tubes in any position in any amp that I have for some reason. Way too boomy in the low end and harsh at the top.

I had great luck with TAD7025 (which is Chinese production I believe) and Sovtek 12AX7LPS. Both sound great, no noise issues whatsoever.
I am using TungSol 12AX7 reissue for V1 of the Asteroid/k60 build and find it best sounding out of the bunch for V1. No noise issues whatsoever.

Maybe I got lucky - I usually purchase them from Banzai Music Gmbh here in Europe. They have some sort of selection, matching process going on, but didn't have any issues.

I use Sovtek 5AR4/GZ34 as rectifier, based on what Komets are using and seems to run good and stable.

I have few NOS tubes that I am using as reference here and there, but I would generally agree - the chances to get good NOS tube will get quite slim in just a few years from now, so new production is the way to go.
(I got a bunch of Sylvania/RCA 12AV7 for one of my other builds, using them, though :)should be good for more than few decades )

Niki

[billyz]

Can concur with Syncro. I tried a set of sovtek 6ca7 in an express build and it sounded very good. I then switched to a matched set of rft's and was surprised at how close the soviet 6ca7 came.
Spiral filament Tungsols do not do well in a cathode follower , for that I use the sovtek 12ax7wb.
I had a case
Of 100 JJ 12ax7 and found a few duds , they were a bit darker sounding than some other brands, but ok . I will not use JJ gz34 anymore. The sovtek 5ar4 has been much better for me.

[Littlewyan]

Thanks for the feedback guys, interesting.

I havd heard of reliability issues with JJ Valves but tbh I've heard that about every manufacturer. Plus I just think this is one person out of perhaps thousands that buy JJ Valves.

I also have a Tung Sol 12AX7 in my V1 and its great. Pretty much the same as the JJ tbh but I didn't do a proper comparison. I looked at 6CA7s and have heard great things about them but I think I'll start with EL34s.

Now is there a noticeable difference in headroom between the JJ EL34 and the E34L?

[Littlewyan]

Well bloody hell, one of my EL34s has a dead heater. Hardly used these valves!!! Luckily I had a spare from an old pair where one went bad. They're 7Ma apart but will do. Anyway the Winged Cs have a very muffled bass, not tight at all. Really makes me try to avoid playing power chords on the Low E string. Also there was extremely little difference in headroom. Moving towards buying the E34Ls.

[thejaf]

It's been quite a few years since I bought any tubes, but last EL34 version I bought and was really happy with was Ruby EL34BSTR, big bottle variety that sounds pretty damned full. have not tried in Express, but in classic Marshall circuits. Assume they're still being made.

[Littlewyan]

I've just ordered a pair of TAD EL34B STRs which I think are slightly similar to Rubys. I believe they are made in China but to TAD's spec. Anyway TAD match them and then they're burned in and matched by Karltone (supplier I use). So in theory I can't go wrong!

[Synchu]

These are good sounding and reliable. I have a matched quad in my Diezel Einstein and been happy with them for quite a while now.
Niki

[Littlewyan]

Yer I've heard a lot of good things about them, I know you can't judge tone by reading reviews but I haven't heard much about them going wrong. Plus like I said I think they're tested quite a lot so fingers crossed.

[Littlewyan]

The TAD EL34B STRs arrived today and they're brilliant. Both perfectly matched at 40Ma each and sound great. I only got to play on them for 10minutes so didn't test them that much but I liked what I heard so far.