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In need of a rewire diagram

vroom_vroom

vroom_vroom

Member
I'm hoping someone with more tube knowledge than me can help me out. My tube amp is using a ecc83 preamp tube that feeds into a 12ax7. I am wanting to rewire the ecc83 to. 12ax7 so I can use the same tubes for each socket I'm just not sure what wires I need to move around. Any help would be greatly appreciated. If you have a digram you would be my hero!!


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Most 12AX7/12AU7 family of tubes have a tap for 6.3 or 12.6 volt operation. Most of them are used in the 6.3 volt configuration.

Look at the taps at pins 4, 5, and 9. 9 is the center tap so if you tied pins 4 & 5 together along with the center tap, you would get the 6.3 volt operation. Leave pin 9 out of the equation and use just pins 4 and 5, you would have a tube that operates on 12.6 volts.

http://www.mif.pg.gda.pl/homepages/frank/sheets/093/1/12AX7.pdf
 
Doh!! It's a 6eu7!!!! Not a ecc83!!! I was looking at the wrong tube!

How about a rewire for the 6eu7 to a 12ax7?


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Why is that? What are the "ill effects"? The way it's set up the 6eu7 feeds into the 12ax7 and the 6eu7 has a good bit of micro phonics going on.


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I was going to say, "microphonics". The 6EU7 was Magnavox's 12AX7 without infringing on patent rights.

Personally I would rather have a 6EU7 but they are supposedly getting scarce where as the 12AX7 and their variants are plentiful. This is why I rewired my tuner/preamp to take a 12AX7.

Plus, the 6EU7 only operates on 6.3 volts.
 
Sovtek is making a 6EU7 now, I have not tried them but I've had reasonably good luck with other Sovteks.

Probably it's a re-pinned 12AX7WLPS (I think that's what Sovtek calls their low-microphony tube).
 
Humm not sure, the 12ax7 tubes I am running are really 7062s have not had any micro phonics out of it when I run just that guy and not the 6eu7 that feeds into it so my hope was that both of them would be better than just one.


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Digging through the archives I found an old post from roggom. Can someone confirm this procedure for me?

"Not sure of what amp you are modding, This will be some extensive soldering as the 6eu7 is completely wired different than the 12ax7.
Download both datasheets here and have them for a reference. http://tubedata.itchurch.org/sheets11.html

One more thing, the 6eu7 is 6.3 heaters and the 12ax7 is 12.6 you will be running the new tubes with the filaments in parallel.

Since pin 3 is blank we will start there.

Desolder pin 4 wire and solder it to pin 3

take pin 2 wire and solder in pin 4

take pin 5 wire and solder in pin 2

Make a jumper from pin 4 to pin 5

desolder pin 9 wire and hold it off to the side

take pin 1 wire and solder it to pin 9

desolder pin 6 wire and solder it to pin 1

desolder pin 7 wire and solder to pin 6

desolder pin 8 wire and solder to pin 7

take pin 9 wire ( that was off to the side) and solder to pin 8.

Now you can roll in 12ax7 12at7 5965 etc."



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Did you not look at and study the diagrams of both tubes, or don't you understand how to do it?

I just write down in pencil both diagrams and their connections and then just move the wires to the correct locations. Without going to the diagrams themselves, I believe you only need to move 3 or 4 wires but I will look later. Too busy watching "Person of Interest" hee hee, west coast time.
 
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Well in all honesty I don't fully understand how it works so I'm a little lost on what it is I am moving around. When I found that it seemed like a pretty fool proof guide on how to do what I need to do. It's hard to fudge up "paint by numbers"


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YUP! Follow those instructions you posted in post 13.

If it's too much of a hassle for you, you can always have someone else do it for you. What state are you in?
 
im in nevada, im half tempted to have some one a bit more knowledgeable with it give it a go, there are a few resistors/ jumpers on there in its current state im not so sure about
 
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