Groove Tubes EL34LS vs SED


i have a amp air tight ATM-3 to be precise that currently uses Siemens EL34. I want a bit more dynamics especially at the bass. Has anyone tried these? The Siemens seem at the end of their life, although they test fine in a tube tester, the bias cant be adjusted sufficiently high. Since I got this amp recently (used) I dont know if the lack of bottom end is due to old tubes, or just the amp itself.Advice appreciated THX
whodiini
If the output tubes can't be brought up to their proper bias setting; they're shot and you've lost your dynamics. Replace them! If you were happy with the Siemens when new(excellent tubes), purchase another set(or at least a set of SEDs from the St Petersburg plant). ( http://www.upscaleaudio.com/bEL-346CA7-Typesb_c_86.html )
I've had the Air Tight Atm 3s for a number of years. I replaced the Siemens AEGs a long time ago, and substituted Tesla E34Ls, which gave me a more extended top end and more life. In time, like many, I made a number of other changes in my system. Several months ago, largely out of curiosity, I reinserted the Siemens tubes. Compared with the Teslas they produced a warmer, airier sound which I found very attractive. Surprisingly, they had a very nice top end as well, and they certainly didn't suffer dynamically. I must conclude that since I had changed the playing field in other respects, those Siemens tubes began singing a "different tune". But, I've temporarily removed them again and put the Teslas back in, since I've been experimenting with alternate approaches to fune tuning. It's nice though to realize I've got this most welcome "ace in the hole". Anyhow, if your Siemens' tubes are ready for burial, then put them out of their misery. Too bad you don't have access to a tube tester. Otherwise, you might want to try the Teslas. I've not heard the SEDs, but based on what I've read, they might not exhibit the kind of top end extension the Teslas have. Regarding your desire for more bass dynamics, that of course is a matter you will have to experiment with. Certain combinations of tubes and cables have given me more dynamic bass reproduction than others. You might want to try different tubes in the 12ax7 and 12au7 sockets of the Air Tights. I've consistently derived great musical satisfaction from Mullard 12au7 "boxplates". Depending on your sound preferences, you also might want to sample pre-war Ei Yugo 12ax7s, Telefunken 12ax7s or Brimar 12ax7s along with those Mullard 12au7s. Another alternative would be the RCA "cleartop" 12au7s in tandem with the RCA long gray plate or long black plate 12ax7s. The long grays might sound somewhat more exciting, and the long blacks somewhat more relaxed but musical nonetheless. As for cables, that's another complex, system dependent issue. Perhaps some Cardas Golden Reference somewhere in the chain might merit consideration. Best of luck.
Sorry. I overlooked the fact that you DO have a tube tester.
I use the Tesla El-34LS in my Quicksilver M-135 monoblocks. They give the greatest "slam" in the low and mid-bass of any of the tubes I have tried (but I have never tried the Siemens).
to Gmuffley - are the groove tubes el-34ls teslas? how is the high end? The Siemens high end is fine, but not the "slam".Have u compared with the SED? I'm about to buy new sets and its between the groove tubes and sed. Based on this feedback, i may go for the groove tubes. BTW, i am running Brimar 13D5 and Sovtek 12AX7LPS NOS circa 2003. cables are the new Oval 9s. THX everyone!
Whodiini...Aside from the original TeslaE34Ls I also have JJ Tesla E34Ls which, to my ears, sound extremely good too. You might want to check out the BOI AudioWorks site.
By the way, For what it's worth, I have tried the Brimar 13D5s with my Air Tights. Though they present a very nice sound, I found them somewhat light in the bass (the area you are concerned with). I strongly recommend you try those Mullard "boxplates" in the 12au7 sockets. You might be pleasantly surprised.
el34's are supposed to be light in the bass...alays have been and ill be....their magic is the midrange.
to Gmuffley - are the groove tubes el-34ls teslas? how is the high end? The Siemens high end is fine, but not the "slam".Have u compared with the SED? I'm about to buy new sets and its between the groove tubes and sed. Based on this feedback, i may go for the groove tubes. BTW, i am running Brimar 13D5 and Sovtek 12AX7LPS NOS circa 2003. cables are the new Oval 9s. THX everyone!
Whodiini

It is my understanding that the JJ/Tesla El-34LS and Groove Tubes are the same. The ones that I have were made in the Czech Republic and were purchased from Penta Labs. The high end response is excellent, but perhaps not as good as the very best El-34 tubes. The SED tubes are very nice, but don't have the slam of the El-34LS.

07-08-09: Jaybo
el34's are supposed to be light in the bass...alays have been and ill be....their magic is the midrange.
Jaybo (Threads | Answers)

I would agree with you if El-34 tubes are used in ultralinear or triode mode, which is the case with the vast majority of amps. The same is not true when run in pentode mode with a regulated screen grid supply, as is the case with the Quicksilver M-135 monoblocks and the original Quicksilver MS-190 stereo amp.
Generally speaking, and relative to the other biggies, EL 34s tend to be a bit bass shy, however, with the right match of components, including cables and other smaller tubes like the 12au/ax7s, one can cull some very respectable bass reproduction. I listen mainly to large scale orchestral music and really don't feel I'm missing much in terms of heft/power. More than likely, though, the fellow who drives his car past my house now and then would disagree.
Consider Groove Tube EL34Ms made by Mullard; very dynamic and spatial in my Cary V12R. Another key with this amp is the use of BZ7 input tubes. -Lars-