EI EL84s

[Aurora]

Just aquired a dozen of EI EL84s as part of a trade....
Any opinions on these?

[Cliff Schecht]

From what I've heard the old ones are great but the ones made in the late 70's/80's can become little fireworks plugged into your amp. Do they have a date code?

[Aurora]

They probably have date codes, but even if I'm just old enough to have had formal lessons in tube tech ( probably of the last ones ), and been fixing amps and transmitters for more than 30 years, this date code thing somewhat eludes me....
Any pointers to solid info on "where and how!...?

[Cliff Schecht]

I should have said lot number, that's more accurate. Amperex and Mullards have lot numbers and where they are manufactured. I don't know much about ei tubes though so I don't know how they labeled them.

[sharkboy]

Higher stress amps (screens and plates) seem to be hard on them, but Ei EL84s sound very good to my ears. I'd say they are made for people that unabashedly like EL84s. They have a strong high end. You might not like them if you are used to JJs. I have had them from a few vintages. I'll take them if you don't want them.

[selloutrr]

Ei EL84 factory data sheet

[pinkmarkos]

I have a quad of EIs in my rocket-ish build and have used them in a matchless lightning type build (15 watter). I would agree with sharkboy's take that they have a forward high end (nice and sparkly to my ears). Not as balanced as the mullards I have, but not as muddy as JJ's. Decent breakup, good complement to vox style amp. Obviously depends on circuit, but overall I really like these tubes- good score