plate dissipation vs brand

[pforeman]

comparing apples to apples (etc) between new manufacturers, does anyone know which el34/6ca7/kt77 can be biased highest before plate glow.
Same for different manufacturers of KT88.
Same again for different manufacturers of 6L6GC/KT66
?
Thanks,
Paul

[richwalters]

The earlier Mullard EL34 was a brilliant and wise tube; unlike the steady amount of trash around these days.

Where's the Mullard /Philips jigs and assembly tools of yesteryear gone ?

richy

[DF96]

Some went to Ei in Serbia, others to BEL in India?

[radiostar]

Originally Posted by DF96

Some went to Ei in Serbia, others to BEL in India?

Yes they came to Serbia ... Almost all other tubes except EL34 were were great tubes and exact Philips copies ... more or less ...

On the other side EL34 EI Serbia is totally different story. In Nis they used smaller glass envelope, it was crisis time and PL36 glass envelope was used, also plate size is a bit less than Philips metal base EL34 and Philips EL34 Xf4 made in Mullard plant in Blackburn. Plate structure different and getter is very similar to Philips EL34 metal base. Some series of these tubes were real dissaster, with so smal power dissipation, but if you were lucky enough to buy factory selected tubes it was nice, great sounding tube, somewhere between real old nos and current production.

I have two of them in one SE amplifier in my office and they work more than 6 years, 12 hours every day!!!

[DF96]

I believe RFT EL34 are supposed to be fairly tough, and still not too expensive for NOS. Slight problem is that most of them are not branded RFT, but Siemens, ITT, Brimar, Mullard, Telefunken etc. etc. You have to learn to recognise what is inside the glass, or trust a good dealer.

[richwalters]

BEL India....(if it is this the correct site..)...with the "push ahead" state financing really puts into place how rundown "industry UK" has become.
The JJ 34 version which I tried was a disappointing performer.....The RCA 7027A which I have a few NOS of, is a very consistent pentode. Coming to this, there's a whole raft of near tetrode power equivalents... On stage I'm not the only one to put a 5881 in lieu to wrap the problems up or even a 6L6.

richy

[costis_n]

Originally Posted by DF96

I believe RFT EL34 are supposed to be fairly tough, and still not too expensive for NOS. Slight problem is that most of them are not branded RFT, but Siemens, ITT, Brimar, Mullard, Telefunken etc. etc. You have to learn to recognise what is inside the glass, or trust a good dealer.

I think they are also labeled RSD.