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
As I stated here before, my favorite among popular tube types are 6L6 and KT66 for pentode/tetrode tubes.  For single-ended triode amps, I like 45s and 2a3s.  For less common types, I like the 349 (a tube I run in my pushpull amps) and 350 (similar to 6L6).  For super rare tubes, I heard an amazing amplifier that ran the 252 meshplate tube.

I've been running an octet of 7581A in a Primaluna Evo 400 power amp. I do like them more than the original EL34 in my system. Sacrifices just a smidge of midrange magic for better low end meat and upper end presence. Just a nice balance from top to bottom. 

Enough to make me want me to keep the Primaluna. 

 

Would the 7581A be biased the same as a 6L6GC/KT-66? I am currently running KT-88s in my DeHavilland 50A mono blocks and would like to try the 7581As. The DeHavilland is designed to accept 6L6/KT-66 tubes and a bias setting for those is specified in the owners manual. Would it be safe to assume that the same bias setting be used for the 7581A?

Would the 7581A be biased the same as a 6L6GC/KT-66? I am currently running KT-88s in my DeHavilland 50A mono blocks and would like to try the 7581As. The DeHavilland is designed to accept 6L6/KT-66 tubes and a bias setting for those is specified in the owners manual. Would it be safe to assume that the same bias setting be used for the 7581A?

I'm not a tech but NO I would not assume that. I was running Heathkit W5 monos originally with NOS GE 7581A. When I switched to reissue Gold Lion KT66, those ran a LOT hotter and my tech had to adjust the bias down so they wouldn't orange-plate. 

Of course you're talking reissue Tung-Sol 7581A which I haven't quite tried yet, but I do have three quads on the way to try in my Rogue Apollo Dark monoblocks :) 

Op, Agreed. I ran some current production “Tung Sol” el34s and for my tastes nothing else came close. I was initially turned off at the exploitation of the name but the tubes/their quality do the name some justice.

 

re. 6922s Although there may be some complications getting them these days, the  Electro-Harmonix are EXCELLENT tubes.

 

I think the superiory of NOS over current production tubes is greatly exaggerated in many cases.

 

All that being said, I once had a pair of telefunkens that were simply divine.