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EF 86 [message #31434] Fri, 18 November 2005 12:05 Go to next message
Manualblock is currently offline  Manualblock
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Illuminati (13th Degree)
What is good to do with that tube; also 6A4's? Any ideas?

Re: EF 86 [message #31435 is a reply to message #31434] Fri, 18 November 2005 13:32 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
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Illuminati (2nd Degree)
It is a good amplifier pentode. Quite similar to the 6SJ7 in terms of electrical properties. As to sonics, probably quite circuit dependant, no?

Alternate designations are the 6267 and Z729

Often used as the first stage in the Mullard amp. EF86>>{twin triode LTP}>>PP finals. Direct coupled usually so as to use an acceptable tail resistor in the phase splitter. The Eico HF50 went EF86>6SN7>EL34 to a nice Chicago OPTx.
cheers,
Douglas

Re: EF 86 [message #31436 is a reply to message #31435] Fri, 18 November 2005 15:30 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
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Illuminati (13th Degree)
Thanks Douglas; I have some available along with some other triode and dual triodes. There's a music place clearing out their back tube lot here but a lot of the types I don't recognise. Those are two I am familiar with and was just wondering whether to pick them up pretty cheap.

Re: EF 86 [message #31437 is a reply to message #31436] Fri, 18 November 2005 16:39 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
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Illuminati (2nd Degree)
Thee's lots of cool tubes worth at least $1 each. Damper diodes, twin and single triodes. That 6A4 looks like a cool driver tube actually. I'll try those if I can find some. Can you say, all DH E-Linear?

Lots of stuff is worth keeping for experimenting with. I wish I were with you to go through that stack.
cheers,
Douglas


Re: EF 86 [message #31439 is a reply to message #31437] Sat, 19 November 2005 06:58 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
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Registered: May 2009
Illuminati (13th Degree)
Thanks; I gotta be carefull or they will become suspicious and start looking on E-Bay or something and then thinking they have solid gold there.

Re: EF 86 [message #31441 is a reply to message #31439] Sat, 19 November 2005 12:04 Go to previous messageGo to next message
Damir is currently offline  Damir
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Illuminati (2nd Degree)

EF86 is becoming rare and expensive, especially "noble" brands, like Telefunken, Mullard, etc. It is not used just in vintage audio (Quad II, for example), but in guitar amps (Vox AC15, for example).
Friend of mine went through many brands for his "Matchless DC30", and eventually settled down with TFK EF806S - good, but costly...

Re: EF 86 [message #31444 is a reply to message #31441] Sat, 19 November 2005 13:01 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
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Registered: May 2009
Illuminati (13th Degree)
Thanks D; I'll look for those.

Strategy [message #31445 is a reply to message #31444] Sat, 19 November 2005 14:56 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
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Registered: May 2009
Illuminati (2nd Degree)
Hey-Hey!!!,
You might go and hunt up some inexpensive tubes. Something like a 12AX4. That way, when/if they go looking, it will come up as a cheap-O. You might want to do this more than once, while you make a mental and more complete inventory of the cache.

Also consider that you are consuming large quantity of profit by sorting the tubes for the ones you want. Unsorted selections from TV shops are rarely worth a dollar each. If you pick out a few good ones, you have spent time doing so...

Proceed with caution and care, and above all, leave nothing useful behind when you are through.
cheers,
Douglas

Re: Strategy [message #31446 is a reply to message #31445] Sat, 19 November 2005 15:41 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Clever; very clever! Now why didn't I think of that?
Thanks; I'll keep you posted.

Re: EF 86 [message #31447 is a reply to message #31436] Sat, 19 November 2005 20:13 Go to previous messageGo to previous message
2wo is currently offline  2wo
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Registered: May 2009
Baron
Hi M,
the EF86 can be a very useful tube.
When I converted my JE labs 300b to a WE 91 type I had to decide between the ef and the 6js7.
Good ef86’s were not cheep,
In the end the 6js7 would fill the empty octal hole with no fuss and I did score some very nice old, old ,stock glass 6js7. So there I went.

Get them if you can, contrary to popular opinion, pentodes are not evil.

If you are not inclined to use them as an input stage. Should you ever be inclined to use a Gary Pimm pentode CCS, your good to go…John


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