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Tube Question


loos
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Hi,

I've got a small amp I like a lot, it's a combo amp labeled "The Vibe" Model 1259. I play it a fair amount and want to have spare tubes on hand but I can't read one tube, all the numbers are worn off. I can't find a schematic on the web or haven't yet so... anyone have an idea what I need. It uses two 6CA4/EZ81 tubes and one 6V6GT and the mystery tube which I would guess would be a 12AX7 but really it's just a guess.

I'd sure appreciate any help on this,

loos

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While searching for the model that you listed I was able to see a couple of photos of the rear of one and there was definitely an 12AX7 in the picture. The strange part was that the photos showed 2 AX7 tubes. If I can find the links again I will add them. Do a search on Massie or st. george and put the amp and model in. Sounds like a neat little amp considering that Massie worked for Fender.

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Found the picture I was looking at... http://www.auctiva.c...,0,0,0&format=0

Hopefully that takes you there, but from what I have read they are powered by 2 6V6 tubes, have one Recto tube and 2 12AX7 tubes. On 3 different sites they mention that combination for that model.

Based on what I have read that the amp was manufactured by either St George or Teisco Amps based on Massie's specs. As I mentioned earlier Massie appeared to be trying to break away from Fender at the time and was expanding. If it is a Teisco Amp I may even have the prints on it, unfortunately I did not have to time last night to dig out my books.

I will let you know if I find anything else, but hopefully that helps get you closer to where you want to go.

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Thanks for the help. It would appear that the pictures at your link aren't of the same amp although many features are in common. Mine however has only one 6V6GT and two 6CA4/EZ81 tubes. I can read the text on those. There is only one other tube and that is the one which has lost its text. I don't see how to attach photos here but I have four small ones which show different tube layout, a similar face plate with some different labels.

I can only guess that some of these were either made differently or were modified by their owners over the years. The St George marque is missing from my amp, perhaps it was built by Teisco...

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I guess I'll find out by buying a 12AX7 and trying it. I know sooner or later I'll need tubes and it seems like I may as well be prepared. The amp has quite a nice vibrato so I was surprised not to find two 12AX7 tubes but two 6CA4/EZ81 tubes instead. From what I can tell the 6CA4 rectifies current but what I know about amplifier design is about what an echo knows about language.

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what about a hi res gut shot so we can make a schematic off of it. and also determine if this is a dual triode 12ax7 or what. if you send me some good pics theres a real good chance i can reverse engineer it

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Gasp! It would appear that I've been completely mistaken, somehow I got my drawing with one end duplicated, I guess it was not really taking the amp apart but having taken another set of pictures I see that it's not so unusual and strange in reality. Two 12AX7 tubes, a 6V6 and a EZ81. The second 12AX7 is different looking from the first. I gather one does the tremolo and the other is preamp. Funny how reality is less strange than delusion. Still happy to post once I figure that part out. I guess the first step will be to donate.

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email me the pics and i will post them for you if you like. my emails in the info thing edited ok my yahoo mesenger id is there which is the same thing

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  • 3 weeks later...

Most likely the preamp all the way to one side is the input and tone stack tube, the other is the tremolo driver. As far as spare tubes, untill I found what I was looking for I would get a couple of cheaper 12ax7s for the preamp and a JJ6v6 for the power. Try the JJ even though the original still works. You may have a nice Blackplate RCA or something in there, which you wouldnt want to damage, so take the JJ on the road and leave the old tube for studio and home use. Especially if you like the old tube better than the JJ.

For the first tube you can run a 12ax7 or put in a 5751 for 30 percent less gain.

If you really like the amp, then a good idea would be to replace the power supply capacitors. If you know how to solder it would be easy to do. If you amp has a slight hum it will probably go away. Also, above all else install a three prong cord. And if it has a ground switch on it then you probably need to remove the "death cap".

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just to let you know i got the email with the pics in it but accidentally deleted it if you can resend i can still look at it.

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I don't understand "death cap" except when it's a mushroom. Then I just know not to eat it.

I'll look into replacing the power supply capacitors, I've a friend who can help me identify them and I can solder reasonably well. I do have hum. There is a grounded cord on the amp. When I got it the tremolo didn't work so a local tube amp specialist Skip Simmons, went over it, restored the tremolo and added the grounded cord.

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  • 3 months later...

btw i have about a third of this done. working six days a week for the last several months is exhausting.

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