Really...My favorite power tube is reissue that's not widely popular


If you run 6l6/EL34 variants, I HIGHLY recommend trying this tube out.  The Tung Sol 7581A reissue.  I've had these for a good bit of time and compared them against KT150s, EL34s (several brands), KT88s, and maybe another that I'm forgetting.  They are a mere $30 a pop and they are the best tube I have heard. I know that's a brave bold statement to make as there is so much competition out there and the tube is very much under the radar from what I can tell.  

After having these around for a long time (and in and out of the amp), I had them in and was nearly spellbound one night by how great they sounded upon reentry into my amp.  I did a search and could only find one review, which I agree wholeheartedly with.  You can find it here: https://wallofsound.ca/audioreviews/amplification/6l6-vacuum-tube-review-tubes-courtesy-of-www-thetu...

I am nearly incredulous there isn't hype out there about this tube.  Simply my favorite tube.  I thought I'd pass this along as it may be much cheaper to give them a whirl then fuss with a much more expensive power cord, cable, or other tweak.  
128x128jbhiller
@metman Not a huge change as they burn in but they do loosen up becoming less dry and more open.
The blue glow actually got a little bluer after a few days, so there's that, and after however many weeks I've had 'em I've become even fonder (is that a word?) of these things. A classy tube.
Metman, Can you share some details on your “Eico HF-20 JWN” amps?  Are these Eicos rebuilt by Jim Nichols using his input/driver circuitry?
@salectric 
I bought these second hand And actually traded an .EL34 based  amp purchased through Jim  (which was also stellar) and some cash for these which was modified with Jim’s circuit.  I forgot how good these sound particularly with these tubes as they’ve been on the shelf for a couple of years. Jim did comment to me that these were one of his best amps. It’s a shame he’s no longer in the business
@metman 
 I suspect the amps I am using right now look and sound similar to yours.  I used HF-22 chassis (monoblocks), stripped them of all parts, and then rebuilt them using Jim Nichols’ circuit.  I kept the Eico output transformers (same as in HF-20) but everything else is new.  They sound great!  

Right now I am using RCA blackplate 6L6GC from the 1960s but I also have some SED Winged C output tubes that sound really good too.