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Modern Tung-Sol 7581a Tubes

T

Treyphan

Member
So I recently purchased a Quad of Tung-Sol 7581a tubes.
After seeing a few glowing reviews, from “so-called” modern tube “haters”. I figured for the cheap price....why not?

I’m a Big 6L6 amp guy. So I had plenty of amps to try them in. I’m usually a Vintage NOS tube guy only, if I’m buying them. However, with Tube Prices getting out of this world, especially on 6L6GC tubes. I decided it was worth the, relatively small cost as a test.

I received them about 2 weeks ago, and have over 100 hours on them now. So they are certainly “broken in”, if you believe in that. Not looking to make this a thread about that.

Anyway. First amp I tried them in was a Stromberg Carlson ASR-444/Stereo 60. (Accepts 7027/6L6/etc)This is a wonderful 30 watt stereo amp, that I recently COMPLETELY restored. I love it. It originally ran a Quad of RCA 7027a’s, which are still measuring nearly NOS and that I love. Anyway, I couldn’t believe my ears once the TS 7581a’s were installed. Pure bliss. Nice across the entire Freq Range and just great. The bass seemed a bit tighter, with a very nice mid, not too scooped as is common with 6L6 variants...still supple and nice though.
Next I tossed a set in one of myMC240’s. Wow. I’d removed a Perfect quad of RCA Blackplates to try the TS. Some stiff competition. Well I loved the sound, so much so I ordered a second quad for my other 240. I run a Strapped setup in my main system. Using 2 MC240’s feeding some Bozak Concert Grands. Theyve never been happier. Even with Blackplates.

I’ve got TONS of 6L6 variants. GE Grey plate’s, RCA Blackplates, Sylvania STR’s, RCA 7027a’s, Couple quads of various Sovteks, GE 7581, and more. So I feel I’m pretty versed in this particular tube family.

I kept waiting for the TS 7581a’s to let me down....and they just DIDNT.

I couldn’t be happier. I’ve got no affiliation with TS or anyone selling them. Just thought I’d mention it and people could maybe try for themselves. Now don’t get me wrong, they are not perfect, and I wouldn’t give my Vintage tubes up for them. It’s just with some of the 6L6 variants becoming quite expensive. Maybe this would help someone.

Also, I’ve read a few posts, all around the web, not here. That have people doubting the validity of the TS 7581a. It’s not just a re-badged 6L6. These are real deal 7581a with 35w plate dissipation. Built well, and sound great.

Hey, try for yourself, don’t take my word for it. Get em while they are hot! Glad to see these and many other Modern tubes really starting to be competition for the Old school stuff. Cause those ain’t gonna last forever.

Enjoy everyone! Hope this helps even 1 person.
 
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Nice post Trey, with interesting result. Indeed TS make excellent new production tubes.

You may try the TS KT66, which is a 6L6GC in a big bottle. Those are nice too.

And I've got to try the 6L6-G new prod ST shape bottle too. I've listen to them in a MC30 and they were fabulous and look awesome.
 
@Brice thanks for the Heads Up on the KT66’s! They’ve been on my radar. Certainly wanna try em. If they sound half as cool as they look, that’d be quite cool!

Also looking at a quad of Winged-C 6L6GC’s. Sure read a lot of good about those!

Bet those MC-30’s were the cats meow with the Coke Bottle TS’s!
 
I thought they performed better for me than the 6L6 as well, in my single ended pentode. Not as lean or as scooped. Ultimately I settled on the JJ KT77's but the Tung Sol is a fine performing tube imo.The KT77 is more like an EL34 mid with more bass and top.
 
fredgarvin said:
I thought they performed better for me than the 6L6 as well, in my single ended pentode. Not as lean or as scooped. Ultimately I settled on the JJ KT77's but the Tung Sol is a fine performing tube imo.The KT77 is more like an EL34 mid with more bass and top.
Click to expand...

@fredgarvin interesting. I’m surprised the JJ’s came out on top for you...not that I’m questioning/doubting you. Just haven’t had much luck with any JJ output tube. Though to be fair, I’ve only tried a few. Cool how we have som many “flavors” to choose from right now.
I suppose some might have considered me a Vintage Tube “Snob”, up until recently. As that’s all I would run. After a few “bad experiences” with modern tubes 5 or so years back.
Glad I decided to try the TS 7581a’s tho! Also glad you found the right tubes for your setup.

Just as an FYI to Tube Newbs. While 6L6 can be used in place of EL34(and their variants) amps. Not all 6L6GC amps can take EL34 variants. If it’s cathode biased, odds are better. However, be sure to check your amps specs before just plugging tubes in. Hate to see someones Amp, OPT’s or other go up in smoke.
 
Treyphan said:
@fredgarvin interesting. I’m surprised the JJ’s came out on top for you...not that I’m questioning/doubting you. Just haven’t had much luck with any JJ output tube. Though to be fair, I’ve only tried a few. Cool how we have som many “flavors” to choose from right now.
I suppose some might have considered me a Vintage Tube “Snob”, up until recently. As that’s all I would run. After a few “bad experiences” with modern tubes 5 or so years back.
Glad I decided to try the TS 7581a’s tho! Also glad you found the right tubes for your setup.

Just as an FYI to Tube Newbs. While 6L6 can be used in place of EL34(and their variants) amps. Not all 6L6GC amps can take EL34 variants. If it’s cathode biased, odds are better. However, be sure to check your amps specs before just plugging tubes in. Hate to see someones Amp, OPT’s or other go up in smoke.
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I suppose the drivers have a lot to do with the final sound as well. Not to mention the loudspeakers in the combination. I know the JJ's have had a rep for early failure but I've heard that's not as true these days. Good point about recklessly switching tube types!
 
OOOPS I read title wrong :(

I had Westinghouse 7591a in my fisher800c receiver and just bought some TS tubes to try almost a month ago....

The results are amazing! I am so glad these are made. Mind you my Westinghouse have been in there for a while and might be "tired" but still I have tried JJ/EH as well and TS for the win!
 
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I purchased a matched quad of JJ 6L6GCs over ten years ago, for a sound support amplifier that gets rather regular use. When I first bought them, I measured their performance in my power output tube tester, very much expecting them to act like every other Russian copy (of that day) of original American pieces I'd had the opportunity to test: Power output would typically only be 80% of the original American device, and quite often would either slowly rise (with heating), or droop (from a less than capable cathode) under extended power output testing (normally, the test only lasts about 3 seconds max). Whether it was copies of the 6550, EL34, the Sovtek 6L6, or carbonized 6V6s, it didn't matter. None of the Russian tubes could hold a candle to the original American pieces, and the JJ tubes were the bottom of the barrel. The best any of the Russian tubes could ever do was to hold a steady power output over time, but never at the levels that the American pieces could produce. But not these tubes. These JJs were just as capable as any RCA black plate tube I've ever tested in terms of maximum power output, and sustained, stable power output. They all held a steady power output level over extended test time, and even showed a near identical biasing characteristic to the fabled RCA device. Frankly, I was stunned. In my MC 240, they allow both channels combined to developed a sustained 100+ watts RMS, while meeting Mac distortion specifications -- something that only good American pieces are usually capable of doing.

I had occasion to yank the tubes a year or so ago to give them a quick test. All were still producing at least 98% of their original when new power output level. All continued to demonstrate a steady power output level under an extended test time. I continue to be very impressed by the tubes.

Everyone will always have their preferences sound wise, but to me, there was nothing objectionable about the sound of these tubes at all, with their performance proving to be all that the original American pieces were. These tubes had nearly 700 hours on them at the time they were retested. Tube life is this only parameter I'm watching (and waiting) to see in comparison the the American pieces. Time will tell.

The only other tube I have been as equally impressed with is the (relatively) new Gold Lion KT88 reissue. Same comments: Power output is every bit as much as that of the original British pieces, it is stable with extended testing, and has a biasing characteristic that is very much like that of the original tube.

Dave
 
Has anyone compared the several T-S 6L6 variants? I have read favorable comments about each of them but nothing comparing them. The versions that spring to mind are 6L6GC, 6L6G, 6L6GC-STR, and now 7581a.

I recently bought a quad of T-S 6L6GC-STR on the recommendation of Jim McShane, and I am really impressed with them. They hold their own against my vintage quads of RCA, GE and SED Winged C. But now I am wondering whether the coke bottle 6L6G or 7581a might be even better.
 
Any updates here? I was not impressed with my Tung sol preamp tubes that were purchased about 4-5 years ago. 6sn7 and 6sl7. Smeared midrange and lack of bass.
 
fredgarvin said:
I thought they performed better for me than the 6L6 as well, in my single ended pentode. Not as lean or as scooped. Ultimately I settled on the JJ KT77's but the Tung Sol is a fine performing tube imo.The KT77 is more like an EL34 mid with more bass and top.
Click to expand...
After trying various tubes in my ST70 I settled on the JJ KT-77's also. They have a nice well. Balanced sound and.good bass.
 
pjrengineer said:
Any updates here? I was not impressed with my Tung sol preamp tubes that were purchased about 4-5 years ago. 6sn7 and 6sl7. Smeared midrange and lack of bass.
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I'm using TS 6SN7's in my preamp and I dont6 notice any smearing or any lack of bass. I've been using them for about a year now. They did take 30 or more hours to settle in though. Then one day they just opened up and sounded much better. I like the TS 5881's also. The 5881's sound better than several 6L6's I've tried.
 
I enjoy a set of Westinghouse 6sn7 which had a tad more top end than the previous rcas. For 6sl7 I really enjoy this Ken-rad tube I have. They sound much better in my st70 than the Tung sol. But the more recent production ones could be better than mine.
 
I will say I enjoy the gold lion kt77 but only have the eh el34 to compare them to. Both Russian tubes.
 
Got a pair of the TS 7581a yesterday and put about 1.5h on them. Impressive! Looking forward to more listening.
 
I have a pair of the Tung-Sol 7581a tubes in my Dennis Had Inspire HotRod amp. They are the best sounding tube I have tried and I have done a lot of tube rolling, My second favorite tube in my Dennis Had Inspire HotRod amp is the National Union 350B, but they have got extremely pricey.
 
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