EF86

[bitsandvolts]

Hey folks,

what's your opinion on these....tone, sound, microphonics?

-Frank

[jaysg]

It's basically a fun option to have. It is chimey-er (is that a word?). If you build something, you should plan on shock-mounting the socket. I'd be reluctant to recommend it for a single channel amp you'll gig with, unless you carry spares.

[bitsandvolts]

Interesting....so they're fragile, eh?

[Chiba]

That's what I've heard. I'm a relative newbie - both around here AND to circuits with EF-86 tubes in them, but everything I've read and been told says that they sound X and Y, but aside from any reliability issues a particular tube might have, they are in general rather sensitive to things like shock. Basically the word I've gotten is it's not smart to gig w/o a spare handy.

Check out this link, another thread down farther has some info too.

--chiba

[Reason]

There is more to an amp than preamp tube sellections, but since I got an amp with an EF86, I find it hard to play anything else. I don't know what (beyond some extra gain and a little more highs) that I attribute to just the tube. I have a Gabriel Voxer and just couldn't live without it.

[DutchMarco]

Yes they're more fragile than ECC83s. Vox stopped using them because the bass players would make them go microphonic. No problems with guitarists. At least this is how it was written in Dick Denney's book (and I suppose he can tell!). That was with '60s Philips/Mullard production; Svetlana's are presumably more fragile!

You should carry spares and you should also shock-mount the socket, and preferably also the chassis and cabinet but my limited experience with EF86s is that they scream! Provide a stage after it that can distort, I suppose the PI will do the trick. In the amp I've made (SE with PCL86 power tube), it's probably the ultimate lead tone!

I've been told that the trick to smooth pentode distortion (if you put a stage before it) is to remove the Rk bypass cap. Don't know about the Rg2 bypass cap (to ground)...