[connieflyer]

Okay CJ, I'll give you this one, and I really really really mean it this time these tubes are the last ones I'm going to buy. Of course I said these tubes so if it proves that a quad of these are even better then a pair with a pair of 11s I suppose I could squeeze in one more pair! Now that should be interesting if this tube will indeed work as a driver in our amp as well. Reminds me of the days that I used to use a quad of 6s N7 tubes and that was interesting. Well I wish you good luck on the journey I got shipping notice from misses exit my adapters shipped two more days until the tubes arrived from Canada so I'm back to being an international shopper. Good luck all

 

[hypnos1]

Better than 38s or 39s??

Ah now then tr, that's the proverbial $64,000 question lol! And one with no easy answer just yet, with only about 18hrs on the second 7581A as power.

However, even at this early stage, my antennae are giving me some clues at least... in my system! :

1. With the Valvo EL11s back as drivers, despite the PsVane CV181TIIs partnering extremely well as drivers, they don't have the 'polish' of the EL11s (I suspect with the 'standard' plates also...). But I myself have always found this with whatever power tubes used anyway lol ...

2. Better than 38s or 39s?... Although too early, and without proper critical comparison yet, I think I can safely say that the 7581A (Russian reissue Tung Sol at least!) gives a better, more balanced overall performance than the clear glass Mullard EL38 IMHO. The silver banded Philips (France) EL38s - and EL39s - will probably be a closer call, but then, mine have many more hours on them than the Tung Sols. And although the latter's bass is very good indeed, at the moment it doesn't hit quite as hard as my 'special' Mazda EL38/EL39 combo...but there's plenty of time yet, especially as other users of the 7581A say it needs up to 150hrs before at its best (and that'll be when pushing it harder than our amps, so could well be a minimum...and looking at the size of its single plate, no wonder lol! ).

3. Lower/mid mids are definitely more in evidence than most other power tubes I've ever used, and again at the moment at least, along with the enhanced bass, mean slightly less 'air'...but apparently this does change somewhat with further burn-in. All I can say is that if - as is usually found - the EL34 has even more pronounced mids, then it certainly would become the 'syrupy' that some folks find, and certainly not for my tastes lol!

4. Treble is sweet and with good detail, but as I mentioned before, probably a tad short in the 'sparkle' stakes if one craves that kind of sound, or in a system that is already on the dark/very warm side.

And so I'm impatient to be able to do a full and proper comparison with 2x EL39s, and then my 'ultimate' challenge of the 'special' combo...but I must try to be patient a while longer! ...CHEERS!...CJ

 

[connieflyer]

Nice comparison, I hope you get more hours on these. I would love to hear the difference you hear with the pair of 7581a's and then compared to the special El 38 and El39 combo. My adapters should be here in a week or so and then will start burnin. Has the blue glow developed any more over time or pretty static?

 

[hypnos1]

Nice comparison, I hope you get more hours on these. I would love to hear the difference you hear with the pair of 7581a's and then compared to the special El 38 and El39 combo. My adapters should be here in a week or so and then will start burnin. Has the blue glow developed any more over time or pretty static?

Hi cf...about to Don (sorry D!) my Empyreans after another 5 hours or so and see whether that bass is hitting harder yet...the acid test will be if (and when?!) it can do so at low volume level, which is what I find remarkable about the 'special' 38/39 combo, and without being too dominant when given more juice...such a feat I've never found any other driver/power combination to match ...CJ

 

[connieflyer]

I did notice that myself. Then at lower volumes it does not lose the Baseline like some of the other combos that I've tried. Keeping my fingers crossed for these new tubes while we can still get them at a cheap price! And speaking of price oh, such as it is if this comes close to the combo that we like so much with the special 38 and 39, they'll give those chance to rest up a bit and still have an enjoyable presentation. Hurry up and get these burned in oh, so you can try a quad!

 

[hypnos1]

OK @teknorob23 , @connieflyer and all those I know are waiting to hear how things are progressing with the Tung Sol reissue 7581A...with over 100 hrs and about 24hrs on the right and left tubes respectively, I have just experienced one of those moments I've mentioned before that can happen during tube burn-in...ie. a sudden, unexpected leap in performance : stage has suddenly opened up and is now much wider; that bass is now hitting even harder and with excellent detail and control; mids are also not trying to hog the scene quite so much (which I'm glad for, actually! ), giving treble a bit more head and 'air'. In other words, an even more balanced and cohesive sound.

And if just to confirm that these changes are real, my own indicators - more so than toe-tapping, for me - ie. eyes opening wide as if taking something stronger than is really legal(!); almost unable to move, and shivers up and down the spine have just hit me big time. That such a sound can come from tubes at this price is bordering on the criminal lol!!

In other words, folks, don't hesitate...just get hold of some of these Russian reissue Tung Sol 7581As (with the 3 holes in the plate) ASAP. I posted a link recently for what looks a good deal on ebay.com (USA), and @teknorob23 linked a good source for UK/Europe. And adapters are available from either xulingmrs (at $27 the pair incl shipping) or member Deyan (Bulgaria and at $40 the pair incl shipping).

All I can say @ZRW0 is I suspect that using this tube triode-strapped could very well be delivering an even better performance than is already acclaimed by users as pentode in power amps (which is often the case of course, with strapping giving a more linear performance ). And so I - and everyone else - must thank you once again for that inspired suggestion for me to convert it and try in our amps...CHEERS!...CJ

 

[ZRW0]

OK @teknorob23 , @connieflyer and all those I know are waiting to hear how things are progressing with the Tung Sol reissue 7581A...with over 100 hrs and about 24hrs on the right and left tubes respectively, I have just experienced one of those moments I've mentioned before that can happen during tube burn-in...ie. a sudden, unexpected leap in performance : stage has suddenly opened up and is now much wider; that bass is now hitting even harder and with excellent detail and control; mids are also not trying to hog the scene quite so much (which I'm glad for, actually! ), giving treble a bit more head and 'air'. In other words, an even more balanced and cohesive sound.

And if just to confirm that these changes are real, my own indicators - more so than toe-tapping, for me - ie. eyes opening wide as if taking something stronger than is really legal(!); almost unable to move, and shivers up and down the spine have just hit me big time. That such a sound can come from tubes at this price is bordering on the criminal lol!!

In other words, folks, don't hesitate...just get hold of some of these Russian reissue Tung Sol 7581As (with the 3 holes in the plate) ASAP. I posted a link recently for what looks a good deal on ebay.com (USA), and @teknorob23 linked a good source for UK/Europe. And adapters are available from either xulingmrs (at $27 incl shipping) or member Deyan (Bulgaria and at $40 incl shipping).

All I can say @ZRW0 is I suspect that using this tube triode-strapped could very well be delivering an even better performance than is already acclaimed by users as pentode in power amps (which is often the case of course, with strapping giving a more linear performance ). And so I - and everyone else - must thank you once again for that inspired suggestion for me to convert it and try in our amps...CHEERS!...CJ

You're very welcome Sir.
I'm myself totally fund of those cheap, easy to find reissued tubes.
Combined with quad CV4003 (Military Millard NOS of late 90's) as drivers, Empyrean is just absent on my head, i'm surrounded by music, details and dynamics as they should and always must be.
Somehow the analysis of sound, wondering if it is right or better this way, or this way with an other tube has come to an end for me.
It's just the way I found the most enjoyable and the way I'm pleased the most with the Empyrean.

Cheers,

Erwan

 

[ZRW0]

And it glows blue on my system !

 

[Scutey]

Well I have just purchased a pair from Hotrox , the review of you're progress so far, h1, has whetted my appetite, especially re bass, as I love deep, fast, hard hitting bass, if they equal or even come close to the EL38 I shall be a very happy bunny, and these will absolutely, definitely, 100% the last pair of tubes I will be buying! .

 

[connieflyer]

Good luck on the no more tubes buying! I've been trying to say this for the last couple of years, so far it hasn't worked very well. Although with the increase enjoyment with this amplifier I'm not sorry that I bought all these tubes.

 

[DecentLevi]

Well before everyone says it's their last tubes, I have a question - why have these tubes never been explored for adaption in the Euforia:

EL34, 6L6 / 6V6, KT66, KT77

Many of these are renowned as top power tubes for many of the best amps and most experienced users, and the KT77 said to be even better than EL34. I got some fantastic looking GEC KT66's for my upcoming amp. It looks like those are all around 6.3v / 1.5ah so wouldn't they just need an adapter, or is the architecture wrong?

 

[Scutey]

Lol well I absolutely mean it ... until the next nice tube appears! .

 

[connieflyer]

Yep

 

[DecentLevi]

Well folks, much to my bemusement, the 7581A IS A TYPE OF 6L6 / 6V6 and is also interchangeable with KT66. I believe KT77 and KT88 are interchangeable as well! So don't go out and try this just yet, but my working theory is that your 7581 adapters should also work for 6L6 / 6V6, KT66 - and maybe even KT77, KT88 and EL34. Perhaps @gibosi can chime in?

Furthermore it looks like the 7581A's must indeed hold their weight extremely well amongst counterparts. Interesting read, thanks to @leftside - Also let folks here know what are some other good options to try among these?
https://forum.audiogon.com/discussi...-with-the-tung-sol-7581a-vs-el34-kt66-kt88-6l

 

[LoryWiv]

OK @teknorob23 , @connieflyer and all those I know are waiting to hear how things are progressing with the Tung Sol reissue 7581A...with over 100 hrs and about 24hrs on the right and left tubes respectively, I have just experienced one of those moments I've mentioned before that can happen during tube burn-in...ie. a sudden, unexpected leap in performance : stage has suddenly opened up and is now much wider; that bass is now hitting even harder and with excellent detail and control; mids are also not trying to hog the scene quite so much (which I'm glad for, actually! ), giving treble a bit more head and 'air'. In other words, an even more balanced and cohesive sound.

And if just to confirm that these changes are real, my own indicators - more so than toe-tapping, for me - ie. eyes opening wide as if taking something stronger than is really legal(!); almost unable to move, and shivers up and down the spine have just hit me big time. That such a sound can come from tubes at this price is bordering on the criminal lol!!

In other words, folks, don't hesitate...just get hold of some of these Russian reissue Tung Sol 7581As (with the 3 holes in the plate) ASAP. I posted a link recently for what looks a good deal on ebay.com (USA), and @teknorob23 linked a good source for UK/Europe. And adapters are available from either xulingmrs (at $27 incl shipping) or member Deyan (Bulgaria and at $40 incl shipping).

All I can say @ZRW0 is I suspect that using this tube triode-strapped could very well be delivering an even better performance than is already acclaimed by users as pentode in power amps (which is often the case of course, with strapping giving a more linear performance ). And so I - and everyone else - must thank you once again for that inspired suggestion for me to convert it and try in our amps...CHEERS!...CJ

As I acclimate to the wild and wooly world of tube amps at times it seems much of my prior "knowledge" is obsolete or even counterproductive. As an example, I pulled the TS 7581A data sheet just for fun and was struck by the operating characteristics as a triode including 5% THD. In my solid state days that would have me running for the exits! Can anyone explain why that is not an audibly negative factor in this context?