Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: phsyconoodler on June 20, 2011, 04:46:19 pm
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Is there any pentode that can replace an EF86 and do it's job without added gain?
I'm waiting for an EF86 to complete a job but was wondering if there was an alternative.
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anyone have any experience with a 6EJ7? They look interesting.
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I'm not sure if I remember well
may be ef83 ??
Kagliostro
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E80F is a pin-for-pin substitute, and according to some reports on other forums is a damn fine audio tube. When I find one to try, I'll report back
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Yes was ef83
http://www.el34world.com/Forum/index.php?topic=7934.0 (http://www.el34world.com/Forum/index.php?topic=7934.0)
http://freespace.virgin.net/phil.crooks/detail1.html (http://freespace.virgin.net/phil.crooks/detail1.html)
Kagliostro
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6BR7
i was looking into building a stomp box - check out the 6AJ5.
--DL
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Is there any pentode that can replace an EF86 and do it's job without added gain?
I'm waiting for an EF86 to complete a job but was wondering if there was an alternative.
Are you simply curious about other pentodes to try or something that fits in the same 9pin socket w/out re-wiring? Sorry, I'm not sure what you're looking for exactly?
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I don't know of a direct replacement for the EF86. The 6SJ7 tends to perform similarly. Phsyco mentioned the 6EJ7 which looks like an EF86 at a glance. I've been meaning to experiment with these since I have a baggie full of them.
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I've had nice success w/ this little ol' 6ak5/ef95/5654 and it has worked beautifully for me. Since it's a very rugged anti shock/anti vibration tube I've had no microphonic issues and it's readily available and cheap. I haven't pressed it into a bunch of different applications at this time but it sounds good to me and compares favorably to both the 6267 & 5879 so far as I can tell in a SE amp.
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I found an EF806s/6267 tube in my stash.Is this the same as an EF86? I can't find any matches in the tube sub charts.It was in an old amp that I gutted years ago.
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I found an EF806s/6267 tube in my stash.Is this the same as an EF86? I can't find any matches in the tube sub charts.It was in an old amp that I gutted years ago.
Hi phsyconoodler. See my earlier post.
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I popped in the tube and fired up the amp.It sounds lovely! No smoke,no noises and lovely chimey gutsy sounds.
This is likely an Amperex made in Holand 6267 tube.
One thing that's puzzling is it tests shorted on my tube tester when set to the EF86 setting but tests fine on the 6267 setting???
My first foray into pentodes for use as preamps has been successful.
Sweet-ass tone and tons of gain too!
Tubeswell,you mentioned the E80F.That one looks interesting.
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Phsyconoodler did you use it with the standard ef86 values, I guess the correct question you didnt change anything right.
Thanks Bill
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Tubeswell,you mentioned the E80F.That one looks interesting.
Yes - sorry I forgot to post a handy link explaining the E80F (which AFAICT is a Mullard hi-spec version of the EF80)
http://r-type.org/exhib/aaa0486.htm (http://r-type.org/exhib/aaa0486.htm)
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I used the exact values for an EF86 and it works perfectly.
I can't make head nor tails of those tube data sheets! I see an amplification factor of 20 and that tells me it doesn't have the gain of an EF86 so I can't use it.
I'm basically only interested in a pentode that has enough gain to be comparable to the EF86 and just uses the rotary tone dial.They are easiest to implement into an amp.Simple is good in my book!
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EF806S/6267/EF86 are the same tube electrically and pin compatible, EF40 is the predecessor that uses a 8pin rim-lock socket.
E80F is pin compatible, has slightly less slope and g2g1 mu is 25 (EF86 is 38). this tube appears to be electrically similar to the 5879.
EF83 (6BK8) is pin compatible to EF86, however, it is a vari-mu tube. NOTE: shady fleabay sellers are trying to pawn these off as an EF86 replacement. they are NOT an EF86, as the EF 86 is a sharp cut-off pentode.
E804S - electrically similar to EF86 with different noval pinning with slightly less filament draw. it is a hi-reliability long-life tube.
EF85 electrically similar characteristics to the 6AU6 in noval pinning. EF94 is electrical and pin equivalent to the 6AU6.
Brimar 6BR7 seem to be nice AF tube, electrically similar to EF86, but is not pin compatible. still obtainable for reasonable (~15USD) scratch.
-DL
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I see the 6267 replaceable by: 8D8, 6F22, EF86, EF87, EF806F, M8195
AS per SAM'S TUBE SUBSTITUTION handbook 8th edition(TUB-8), 1964
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Thanks for the list. I also found these subs: CV10098,CV2901,Z729