I have an old collection of working pull telefunken tubes and one of them is an ef86.

[flashlamp]

I have an old collection of working pull telefunken tubes and one of them is an ef86. I dont really have a need for that valve , im keeping the 6bq5s el84 the 12ax7 is just an ge. though are ef86 telefunken orginal 60s 70s dynaco pull work good in mic circuts? what is the value of such a tube. I might try the ef86 into a generic tube mic circut.
is it it a good valve I would gather it was used as maybe a phase inverter. took me a while to find it I think I might mentioned it in another thread.

 

[RuudNL]

Recently I found an old Telefunken EF804.
It was according to the data books: 'a low noise microphone amplifier', so I had good hope that it would be useable in a microphone. But unfortunalely, it had a higher noise level than any tube I had tested before...

 

[rogs]

I used the encounter EF86 valves (tubes) regularly during my time as an audio service technician in the 1970s.
My overriding memory of them is that they would tend to become unusably microphonic, as they aged....

 

[RuudNL]

Nowadays it is even rare if you find an 'off the shelf' EF86, that is 'microphone grade'.

 

[moamps]

Recently I found an old Telefunken EF804.
It was according to the data books: 'a low noise microphone amplifier', so I had good hope that it would be useable in a microphone. But unfortunalely, it had a higher noise level than any tube I had tested before...

From my experience I can say that the EF804 does not work as well as a capsule impedance transformer compared to the EF86 although I have not found any indications for this in the datasheets. Probably a problem is in very high input impedances. But the EF804 works great in mic preamps.

 

[Rusan]

I used the encounter EF86 valves (tubes) regularly during my time as an audio service technician in the 1970s.
My overriding memory of them is that they would tend to become unusably microphonic, as they aged....

I've owned two guitar amps with EF86 front ends, that I fed with cheap, old stock Winged C EF86s. When one went zingy to the point where you could hear it ringing when playing, I'd plug in a new one. I went through one or two per year, for several years.

I cringed when a friend found a nice lot of NIB Bugle Boy and Mullard EF86s for his Dr. Z Route 66, and told him they'd be ringing like a church bell in no time. After he ruined the first one in about 3 months, he bought a bunch of Russkie tubes and set aside the good stuff for recording.

 

[andYz00m]

Contact Christian Whitmore, he can give you info and, with a photo, identify what it is. He may even offer to test/buy it from you if that’s what you’re interested in.

 

[TimG]

REDD47 uses EF86 tubes in the first stage.
ive gathered a few vintage tubes including telefunkens from a couple of dealers and after learning what I was doing with them, one gave me a couple of others he thought might sound better in the amplifier. Millard etc.
Haven’t finished building yet…

But as Ian has said, maybe it’s better to base builds on high quality, available in-production tubes. Vintage can be a wild card, especially for a matched pair.