18Watt.com

Hey folks...

The next 1 or 2 builds will have ef86 front ends on them....so I need to know where to get some.

I know JJ is in testing/development for an ef86 that's scheduled for release this summer...but I suspect I'll need one for this first build sometime in april at the latest.

I need something that doesn't cost a left testicle. I keep seeing recommendations elsewhere that you shouldn't put any ef86 into an amp unless its a $100+ NOS tube. Now I'm all for being cork sniffy on tubes...and I am aware that ef86's are fragile....

But I definitely need a few ef86's that will let me get out of the gate without investing a $100 bucks on the first tube.

The sovtek ef86 sells for around 20 bucks...thats reasonable...but how are the sovtek ef86s?

Also, I've seen auctions like this:

http://cgi.ebay.com/RARE-EF86-6267-6J32 ... dZViewItem

Looks like the guy is selling this stuff right out of russia...


Regardless, I'd love some suggestions here, as I'm not sure where to go...I've bought a gazzillion 12ax7s...never an ef86....

-Frank

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Too little too late,but I just watched a quad of nos/nib ULTRONS go on ebay for $61.00.Sorry I didn't catch you sooner.




David Johnson.

EF86 = 6267, also electronically the equivilent of the 6CF8 low noise pentode according to the data sheets.

Heres The Data Sheet

So that gives you three searches, often the 6CF8 is overlooked and cheaper to buy as guys often skip the electronic equivilents.
Trout

I am currently getting great results with Siemens, Philips Dario, old Tesla and Ediswan. All NOS and none of them break the bank (the recommendation to use $100+ tubes only = absolute nonsense!!!). I paid about $15 each for a batch of of Siemens - All work well. Telefunken are good too but more expensive. Look out for occasional Mullard bargains on e-Bay. I don't use the new Russian ones like Sovtek. I always take shock mounting precautions to reduce microphonics even though its not needed with all EF86s.

I hope to build an EF86-based preamp stage someday and I bought a pair of Tungsram EF86s off eBay. Are these known to be good, bad. average...?

I also bought a couple of NOS EF83s on eBay after reading Phil Crooks' "The Camel" article on Ampage. One of them is a Mullard, the other I can't remember. Has anyone had experience with this tube type? By tracking datasheets they appear to be very similar to the EF86, 6CF8, 6BK8, 6267, etc.

Finally, given comments I've read on the EF86's susceptibility to vibration, what mounting techniques do people use to prevent microphonics and/or protect the tube. Is a 9-pin locking tube shield adequate? I thought I read (maybe on 18watt.com?) that someone fit a washer/gasket thing between the tube socket and the chassis. Any ideas?

Thanks,
Coop

I just picked up a pair of Svetlana's (winged C label, svetlana box) (I know, but I don't wanna blow a $100 tube on a prototype) from The Tube Store (http://thetubestore.com/ef86types.html) I've fired up my amp and they sound fine.

Joe

Here's the hard rubber bumper/vibration damper that is on my NEC. It's ribbed on the inside for ventilation. I guess you know that this tube is shielded internally, not externally.

The 6267 is on the right-hand side:

Frank,

I’ve used the winged “Câ€

6SJ7s also have great fat octal pentode tone.

you can get them from www.watfordvalves.com for about £10 up to £40 each.

The Sovtek EF86 is the same as the Svetlana EF86, they're just relabeled Winged C's, although I don't think the St. Petersburg factory makes them anymore. They're erratic quality, and often have more gain compared to a NOS, but they work and sound fine.

Finally, given comments I've read on the EF86's susceptibility to vibration, what mounting techniques do people use to prevent microphonics and/or protect the tube.

I'm using some old Mullards, but using a head cabinet instead of a combo was all I needed to get rid of the microphonics. I wasn't able to use them in a combo format, but in a head they work great.

CSB

PF86/4HR8 are equivalent with a 4V heater. Of the handful I've got the majority of various brands have Mullard etched date codes. And they're always much less expensive.

I found two telefunken ef86´s in an old Rogers stereo and two more then the swedish military was getting rid of old "junk" they all sounds very good in my ef86-ecc83-6v6 homebrew. I really like this tube

I use amps with EF86 mid stage (ECC83, 2 x EF86 and 2 x EL34) so I've tried quite a few varieties. If you want to use these at the input end, you want the best possible. That reduces your options - while the Russian EF86 types are useful intermediates I wouldn't want to use them on the big end, although they'd probably be all right if you get the military spec versions. I would consider any German EF86 (Siemens, Valvo, Telefunken), NOS Tesla, or the long-mesh GB Mullards (not the Philips short mesh which has a hole in the side). Lots of these designs have a tendency to microphony, and all amps I've seen using them have screening cans on the EF86, while the other tubes are left naked.
The ultimate for this purpose is the EF806S. These were made by Telefunken and cost an arm and both legs( a lot of 5 NOS just went for $307 on eBay), but the Tesla version can often be bought a lot cheaper - for a valve specified to work for 10,000 hr they are a real snip.
On the other hand, there are lots of similar types out there which have a different pin-out and are very cheap as a consequence, like the EF860 and E180F - if you haven't built it yet, consider a design with sockets side by side so you can use another type as well.

I've had good luck with Ebay....

Pretty reasonable, Probably around 15-20 bux ea. That will be your best bet.

I've got a sort of theremin going with a P-90 and Svetlana winged C EF86 - both presumably prone to microphony. You move the guitar closer/farther from the amp and the whistle goes up/down in pitch. I'm gonna practice until I can play "I just wasn't made for these times"...

30 years ago I had an SG Special that picked up Radio Moscow in conjunction with an old AC30 head, so I sold the amp for £75 - oops!