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old crow
02-16-2008, 03:19 PM
I'm not getting much response from my thread on the amp section, so...
I have a Fargen Bastage , w/ ef-86 preamp tube. Does anyone here know if a 12ax7 or other preamp tubes can be substituted ?
I really like the ef-86, but I'm just curious how a 12a... would sound...but don't really want to blow it up.:FM

frank4001
02-16-2008, 03:41 PM
To the best of my knowledge....Nope. think someone makes an adapter though..

bigroy
02-16-2008, 04:22 PM
I have been advised that you should not swap one for the other. But then a lot of my advice over the years has not been 100% accurate.....

gtrnstuff
02-16-2008, 04:25 PM
Don't know if you'd fry something, or just no sound, but get an adaptor. Groove Tubes makes one.

rreiser
02-16-2008, 04:53 PM
You cannot substitute a 12ax7 for an EF-86. You need to rewire or get an adaptor.

old crow
02-16-2008, 05:02 PM
You cannot substitute a 12ax7 for an EF-86. You need to rewire or get an adaptor.
That's kinda what I thought.
Thanks for all the quick response.

ruger9
02-17-2008, 08:24 AM
Does anyone make a 12ax7 to EF86 adaptor? Now THAT would be interesting...

guitarstan
02-17-2008, 08:37 AM
I've never heard of such a thing nor would I want to try it.

Check out this site

http://www.guitaramplifierblueprinting.com/index2.html

everything you ever wanted to know about tubes and amp...:BEER

Groovey Records
02-17-2008, 11:05 AM
I'm not getting much response from my thread on the amp section, so...
I have a Fargen Bastage , w/ ef-86 preamp tube. Does anyone here know if a 12ax7 or other preamp tubes can be substituted ?
I really like the ef-86, but I'm just curious how a 12a... would sound...but don't really want to blow it up.:FM

12 ax7 tubes wont fit in the EF86 socket, puting an adapter will just defeat the circuits design. And vice versa an EF86 cant be put in a 12ax7 socket without pop goes the weasel results

In the last month I have tried 10 different types of EF86 tubes each one different yet all lend the chimey ring quality in different shades.

Try swapping a NOS EF86 RFT (tesla) in or a current winged C
I've had great results with those at reasonable prices.

Its very subjective but for me in my amp with VooDoo HB'rs I have loved the Telefunken and Mullard NOS tubes for a little(lot) more$ search EF86

regards
Groovey Records

Blue Strat
02-17-2008, 11:16 AM
12AX7s WILL fit in an EF86 socket and vice versa. The best thing that can possibly happen is that you'll get no sound. The worst thing is a dead tube or possibly burnt components in the amp (not sure about either of these, but it's not worth finding out the hard way).

Goldstrat
02-17-2008, 11:23 AM
I have a single ended amp that has a single ef86 and runs either an el34, 6l6 or kt66 power tube. The ef86 is a brand that I never heard of so I am curious how a NOS tube would sound in it. It is a killer amp. I don't mean to hijack but I would be interested in any advice on which ef86 tubes are good and where to get them. And to answer your question a 12ax7 is a different type of tube (design) than an ef86 so they are not interchangeable at all. I don't know all the details but maybe a 12ax7 is a dual triode and the ef86 is more like a pentode tube.

http://www.johnstafford.net/JJ/Champ_Killer/Dscn1389.jpg

Groovey Records
02-17-2008, 01:28 PM
I have a single ended amp that has a single ef86 and runs either an el34, 6l6 or kt66 power tube. The ef86 is a brand that I never heard of so I am curious how a NOS tube would sound in it. It is a killer amp. I don't mean to hijack but I would be interested in any advice on which ef86 tubes are good and where to get them. And to answer your question a 12ax7 is a different type of tube (design) than an ef86 so they are not interchangeable at all. I don't know all the details but maybe a 12ax7 is a dual triode and the ef86 is more like a pentode tube.

http://www.johnstafford.net/JJ/Champ_Killer/Dscn1389.jpg

Blue Strat AKA Mike K. is a great source for tubes he tests all is goods and stands behind them (but never on top of them)

I have had great results with Mullard, Telefunken, RFT, Tesla NOS Tubes so far the Mullard Mesh Plate 1950's tube has been a favorite

http://www.kcanostubes.com
regards
Groovey Records

Someone I know put an EF86 in P/I and Pop Went the weasel

Blue Strat
02-17-2008, 01:43 PM
[quote=Goldstrat;3679544 I don't know all the details but maybe a 12ax7 is a dual triode and the ef86 is more like a pentode tube.

[/quote]

That is exactly correct.

Swarty
02-17-2008, 02:26 PM
FWIW, EF86s are the most inconsistent tube I've ever come across. Good ones are the best guitar input tube I've ever heard, but you have to weed through a lot of bad/marginal ones (both sound quality and noise issues).

old crow
02-19-2008, 09:43 PM
Thanks for all the info.
This is the second amp I've owned with an ef-86 preamp and like someone said when they're running good they are great, but I've gone thru a few tubes and I too prefer the Mullards.
I find ef-86's tend to produce a nasty distortion ( sometimes ) when driven too hard, which is easily done with humbuckers, so there's quite alot of tweeking your guitar vol. and pedals to find the sweet spot...but when it's dialed in the tone can be pure heaven.