When people were talking about 6F6 awhile back, I got some Tung-Sol black glass 6F6.
They were so bad, I never ventured to try the 6F6 metal people were hyping.

Have a friend with Elekit TU-8800, and was hyping me on them, so I finally got some.
WOW, they are absolutely nutter. Very good.

Not sure how Glass 6F6 can sound so bad, while the 6F6 metal are astounding... eh

https://cdn.discordapp.com/attachmen...4/IMG_0230.jpg

I wonder if I got some bad ones because they had a noticeable glare in my system. Hmm…

Probably not, mine are BRIGHT, very bright.
I'm hoping with some burn in they calm down.

If not, I can roll some warmer 6sn7 in.

I have a quad of NOS RCA metal 6F6 that I've used in my PSE. I find them to be good but not great. Pleasant to listen to, no significant shortcoming. Just a little tamer and not quite as dynamic to my ears and in my system. Really nice on vocals.

But then I'm not a big fan of 6V6 either - I've tried four different brands, all vintage.

Sylvania JAN 7c5 have been my favorite 6v6esque tube so far. I’ve also listened to some black glass Ken Rad 6v6 and some Sylvania labeled 6ez5 tubes that I’m pretty sure are really GE 6v6. They’re all pretty good but the 7c5 has stood out.

I suppose everyone has seen the notice that New Sensor will no longer be shipping tubes to the USA. Brands are Electro-Harmonix, EH Gold, Mullard, Tung-sol, Sovtek, Svetlana and Genalex Gold Lion.

With Shuguang still crippled from the fire at their factory, this will eventually create a tube shortage. JJ will not be able to increase production to cover this. Maybe PsVane or Full Music will increase production?

Perhaps back door channels will develop, where Russian tubes are routed through Asia and relabeled. That has happened in the past.

Personally I have sufficient tubes to last at least 10 years, probably longer.

Just got my metal RCA JAN 6F6 metal tubes circa 1958. Brand spankin NOS, the smell of paint on first warm up confirmed this.
They sound amazing, true to source and instruments just sound right. Haven’t A/B’d with other tubes. But I had EI KT 90’s in there before and wasn’t missing them in my 6V6 amp.
I’m using a 596USAF rectifier at the moment, next I’ll try my Holland 5Y3 as Dennis recommended.

Glad I’ve stocked un tubes years ago! Hopefully the Ukraine crisis is sorted soon, and not for vacuum tube reasons.

Cool Amp by the way! I have a 6V6 amp from 2015. I pair it with an LP-2 preamp with Dact stepped volume pot. I have rigged up a headphone jack directly off the speaker tap’s. but I love the idea of having the headphone jack built right in.
My amp runs my Mrspeakers Prime planar headphones amazingly!
Enjoy!

I figured something like this was going to happen. I just got in a quad of the Golden Lion KT66 and a quad of the Tungsol 7581a tubes. I too now have output tubes to last me the rest of my life and beyond. It’s sad though. I had been snatching up NOS because they are getting scarce but I always assumed the new tubes would continue to be around. By all accounts they are quite good. Oh well…

Famed amp builder and tweaker Dave Gillespie has raved about the new Tung-sol 7581a. Put it through extensive bench tests and found it to be quite good. I'm tempted to get some, but I really like my Gold Lion KT66 and just don't know if the 7581a would be an improvement, given that they are from the same factory and the KT66 are said to be their top of the line 6L6-type.