Tung-Sol 7581A......Wow!!


So, after seeing a few posts about the 7581a I figured I had to try them in my Bob Latino ST-70. Besides, I needed new tubes and I like something different. That's the fun of tubes....well, at least partially.  I installed them and it took some time to run them in. They still may not be run in. I probably only have about 15 hrs on them. The first day was spent hoping they would get better. They did. They are getting there slowly. I'm coming from GL KT-66. These are different. Very promising but the emphasis is completely different than the KT66. I heard some details which I hadn't heard before, yet it was in the lower mids /upper low frequencies. Kind of surprising since the KT66 has great bass. But the 7581 has cleaner bass. I could tell from the beginning that dynamics are a strong suit of the 7581. And the more I play, the more the dynamics expand...and expand. The dynamic range now is stunning....maybe even too much at times. My system is very resolving. I listen mostly to classic rock where the  dynamics
are really emphasized especially by lead guitar.  But the great volume swing makes the  guitar often sound very bright.  I've played in rock bands most of my life (Drummer/vocalist) so I know what live music sounds  like. There is an over emphasis on the dynamics with these 7581a's. I have not heard anything with a wider dynamic range than I experienced last night as I played Molly Hatchet LP. The lead guitarist sounded as if he was playing a hot guitar with a hot amp and an overdrive pedal. I  am amazed at the dynamic range...even though it is over extended IMO. Its kinda like a freak of nature. OTOH, I really like these tubes. Detail and tone are very good but more subtle than the 66's. My wife loves them, though she agrees that they get close to being too bright I can see where these tubes are great for less aggressive music. Not sure about classic rock. Then too, most of it sounds pretty doggone  good........well, until the dynamics grab you and hurl you against the wall (-:. I'm hoping that the dynamics will ease off some. maybe I'll try some classical music and see what the dynamics do. I have the 1812 Overture on Telarc. But that might knock the walls down. Oh well, I just had to tell someone about it. FWIW, I've read nothing by anyone else in pointing out an extended dynamic range. And because everything is so system dependent, I suspect it will ease off with mine.
128x128artemus_5
@wolf_garcia 


No blue glow but very musical. And cheap...if you can find them. eBay is the only place I've found them now. I bought my last set from Cryoset which is not in business anymore
One week of break in. I've played 2-3 hrs every night. Some nights 4 or more. I'd guess I have at least 15 hrs on these tubes....probably 20. I still question these tubes. Everything is good except vocal placement is recessed but not all the time. Its like these tubes are hit & miss. Maybe I still don't have them burned in. I don't know. I'm not a tube guru with 50 yrs experience but I've never experienced the changes I've seen with these tubes. I think I'll put a CD on continuous play and let the amp play all day. I can see the promise of very good sound from these tubes though. So maybe I'll get a treat.
OK, so I let the amp run several hours yesterday before listening last night. Bottom line, no strange noises last night. Everything come together nicely. I do believe these tubes are burnt in now. Sounds good.
OK, I'm here to cap off this mini review of the Tung-Sol 7581A. Though a roller coaster ride prior to being run in, these are  well balanced tubes. If there is a frequency range which dominates the other, it may be the midrange though both high & low frequencies are well represented. They are smooth top to bottom. However,my system is very revealing . My speakers are well known for their midrange clarity. And so, I wonder if this hot midrange is as a product of tubes & speakers which display midrange better than most? Also I am a drummer who cherishes bass and eschews midrange. So I may be more midrange sensitive than others. Whatever the case, everything has settled in now and I find no offense. I would recommend these tubes with one caveat...Patience will be rewarded with a good balance of music
For reasons perhaps too subtle to accurately describe in any meaningful way, I’ve been sticking with GL KT77s for months now as they seem to (here I go) be more dynamic or...uh...something...than the 7581a tubes which I weirdly simply got bored with. I get a coherent and dynamic sound from my 12wpc (or something) little Had amp and Klipsch Heresy IIIs, and am also a drum freak...Bill Stewart’s "Band Menu" is a nice example of proper (meaning you clearly hear everything he’s doing) drum sound to my ears. Another great recording is a one-off from a band I saw a couple of times named Vorcja (album is "Maximalist") where Keith Jarrett’s son Gabe Jarrett is a monster drummer.