Anyone have experience with the Tung Sol 7581a vs. EL34, KT66, KT88, 6L6

BLASPHEMY! Human perception being the key thing in all things subjective isn't always good news or any news...or accurate news anyway. I have only 2 power tubes in my single ended Had amp so it's almost too easy to look at it and wonder, "what if I put THESE back in?" Immediately I hear differences and are those differences improvements? Sometimes clearly, other times they're simply differences that take a while to get that Oh Yeah feeling...or not.

So true Wolf.  

BTW,  I'll get the 7581as back in rotation again to see how they stack up to the GL KT77s.  Both are great tube compliments--I can't go wrong.

What can go wrong is Tube Reversal Compulsion Syndrome (TRCS) where an audio geek can't decide which tubes to use resulting in socket failure and, sadly, tube abuse.

JB, I have been flipping back and forth between the GL KT77's and the TS 7581A's for just under a year and I still can't decide which I like better. I have the same amp as you do driving my Goldenear Triton One's and both do an incredible job. I probably prefer the 7581's a little better as the GL's can sound a bit thin in certain frequency ranges, probably the upper midrange. I keep both around as I consider them both my "go to" power tubes. I find that using a softer input tube with the GL's help quite a bit whereas the TS's can sound great with most any input tube. I'm really not a fan of JJ tubes for hifi, I'm using a pair of their ECC802S long plates for input tubes and they sound fantastic. Cheap to try out too. I've been through so so many tubes to get to this point, I shouldn't even make this post as somebody will make a recommendation to me to try something new, lol. Take care.

@slmccaul , I hear you!  I'm in the same boat.  Both of these are excellent power tubes, and are reasonably priced. Do you have the ability to try KT150s?  

JB, I have tried the KT150's in my previous PrimaLuna ProLogue Premium integrated and they were my favorite non-EL34 type tube. I have tried a few of the KT88 types and all of them left me wanting that warm EL34 midrange. I classify the KT77 in the EL34 category and feel the 7581A's sound more like the EL34 class than anything else. My favorite EL34 was actually a Siemens RFT from the 1970-1980's. Very nice tubes but ultimately sold them after discovering the KT77's and 7581A's. These tubes have enough of the magic EL34 midrange plus do so much more than a stock EL34 that I feel both are the ideal tube for my application. As I always say, YMMV. To each their own.

After a long break from the 7581a tubes, I swapped them back in.  I was using Gold Lion KT77 reissues--great tube. 

The 7581a adds a bit of the power that the KT150 has and it seemingly has more headroom.  But, I say that without checking the specs.  That's how they sound.  

I remember now why I love these tubes. 

Anyone try the new Tung Sol EL34B?

Noromance and all. Glad that I noticed this thread as it is time (again) to replace the power tubes (16!) in my Manley monoblocs and I am intrigued by your comments re the Tungsol 7581A. I have the discontinued Svetlana Winged C 6l6GC’s in them currently, but they are sounding very tired as of late. Any additional comments, especially re longevity, or recommendation of a good source would be appreciated. Amps came stock with Sovtek 5881’s and I have also gone through two sets of NOS GE 6l6GC’s. Favorites so far, the Svetlana’s, but a close call against the GE’s. 

Thanks!

@frogman Hi there. I bought mine from amazon. 8 tubes in 4 monoblocs still running fine. 

Thanks!

@frogman , How do you like the 7581as?  I recently sold my Primaluna and now have a Bob Carver Crimson 275, which runs (stock) KT120s.  I finally got around to trying the 7581as in it and they are really fun to listen to.  Great clarity and sweetness. 

I bought a quad of the Tung-Sol 7581A's in 2017 when this thread started.  I used them for about a month in my PrimaLuna integrated and thought they were good, but went back to  Gold Lion KT-88s, which I had been running since since PL amp was new.

I've gone through three sets of the KT-88s in the interim, but recently had two tubes fail in as many months.  Tried to order some replacements, but found that new Gold Lions were either out of stock or, if available, had become ridiculously expensive.  So . . . I reinstalled the the 7581As and have been using them for a little over two weeks - - They sound really good - - so much so that I ordered a couple of more from Viva Tubes to serve as back-ups.  Too bad the pair costs more than the original quad  I purchased over 4 years ago, but I don't want to be without replacements if one or more of the original set craps out.

@rshak So what changed from when you preferred the GL KT88s?

no romance - when I first tried the 7581As I thought they were good - but perhaps a bit "dry" and not as warm as the KT88s.  Mind you, I last used the 7581As some years ago.  They now sound quite fine - generally well rounded and "warm" .

I mentioned earlier that two of the KT88s I had been using failed in quick succession.  They were getting longer in tooth, and I suppose their sound quality may have gradually changed, i.e., degraded, a bit towards the end of their useful life, thus making any good, fresh replacement tubes sound better.

Who can say?  I do know I'm quite happy with the 7581As now, and I may buy another pair (or even a quad) to have for the next rainy day.

@rshak I found that too. Midband sweetness wasn’t there and they were a little tight. After 20 or so hours, they opened up. I’ve easily 1000 hours on these in my monos (2 tubes each) and they sound sublime.

I would highly recommend Philips ECG JAN 7581A circa late 70’s production … Unfortunately prices have escalated of late. 

Well, I guess one could say I'm sold on the Tung-Sol 7581A.  Bought a matched quad from Tube Depot, which arrived today in good order.  All in, the cost was $210.71.  Together with the low mileage set bought in 2017 and re-installed  a few weeks ago, plus the back-up pair from Viva, with any luck I should be set for the next few years.