Yes there seems to have been some sort of a decline in quality.
This is more so apparent in output valves than in lower current preamp valves like 12ax7 or 12at7 etc.
I guess in the days of pre solid state amplification , the valve was ‘it’ so obviously manufacture and availability were so much more widespread.
Today tube/valve amplification barely enters the domestic market so you’ll definitely won’t find them in some local shop.

My real disappointment in current manufacturers is with Sovtek valves.
Some of their output valves are so poorly manufactured ,… I just cannot relay to you how bad some of the El-84’s I’ve seen come out of that place….
The Sovtek 6L6 is shocking as well.
Out of all the valves I have tried for 6L6 replacement , the Sovtek behaved the most differently…. almost weird sometimes.
Kind of a wider bias range but ran really cool in the output stage.
Consequently the tops seemed brittle, yellow and finite …. not white and open.

I always liked National Electrics… in the Red boxes…..always nice reliable valves
JAN ( joint Army/Navy ) are another great source ,,, as well as Phillips of course.
Edicron ( I think from the U.K ) also make great valves.

I’m using J.J valves for my 12AT7’s and I’m VERY happy with these.
They use old Telefunkin equipment to manufacture their valves and yes there seems to be a classic edge in there. :tu:

:w:

hello seb i hate to say this but i recently replaced the valves in the sebatron because they were getting really noisy .Luckily i know a great guy here in London who did this for me ,we were able to try out a few valves most of them even from the same make were vastly different in quality,ended up taking an old Phillips valve and a groove tubes valve.He was saying the same as you ,that it,s very difficult to get good valves these days ,citing old American valves as the best
if you can get your hands on them.I would like to add that i,m really pleased with the sebatron which just has a beautiful sound to it.julian

yes i've tried quite a few brands out.i agree i'm certainly most pleased with the j.j brand.seems to be wider bandwidth and flavor
i also like the national tubes although they're much harder to obtain

Ok Seb, what are 12Au7's good for? I'm thinking they might be good for line level stuff. The thing is, I have a bag full of new "old stock" valves from the PMG days! I have a pair of genuine mullard 12ax7's, About half a doz of USA phillips miniwatt 12AX7's, A stack of "United" (West German) 12au7's, I have 1 old genuine "RadioTron" 6aq5 and about 6 Original USA phillips el34's. I gave away a pair of these to a friend for recording and freaked when he used them for normal gigs and burnt 'em out in a year.
These are all old in original boxes (deteriating fast). I also have an original old ABC valve monitoring amp (12Watt) which Is going to be my studio guitar amp once I'm finished. I am loathe to part with any of it, but at the moment they are all just gathering dust. I started mucking around with some ideas for the 12au7s for di. Would they work ok for di or are they rubbish as I've never heard of United? All this stuff is circa PMG.

Ok Seb, what are 12AU7's good for?

...cathode followers , phase splitters ,drivers for output stages .....
They're not highly desirable for gain block stages because of their low gain ,, however nice low impedance output stages can be configured with them.
I'm not sure about United but the Phillips are a nice score.The EL-84's could be utilised in Class-A mode for a nice mono block maybe.
Mullards are always sweet., never a problem up top.

Tell you what a good score would be .... some nice EF-86's. :D :tu:

Thanks seb. Line driver was what I was thinking of, not DI. I do remember seeing some designs for pre-amps based on au7's but as you say the gain is not very high. Cheers.