Tube Amp Archive

Do you have multi tap transformer or you want replace it?

it was a fun little puzzle to solve

The guys at magnetic components replied me!
Martin you had perfectly guessed!

Thanks for the diagram! I will print, and keep it! I had measured the voltage on capacitors, when the amp was in standby, when is on, the tension is 468V, and the power trasformer seems less hot then I was use step down transformer. So I think 230V is the better choice, also because the line is 228V...

Ok! First i have tried with the stepdown transformer...seemed all ok. Now I have tried directly with 230V and I have 480V on anodes, is it correct? With stepdown transformer was 420...but I have only 108V instead 120V

Ok, let's go

Black ----> white 2 Ohm
Black----> brown 1,6 Ohm

Black/White ----> white/brown 2,1 Ohm
Black/White----> gray 2 Ohm
Black/White----> brown/white 1,7 Ohm

Cool! Unfortunately now I’m at work and I can’t go home until tomorrow afternoon...
I can’t wait!

Yes, I have three unconnected leads with thoose colors, yes sorry I have 108V to the IEC inlet

here I am! from black and black/withe to gray 99V
From black and black/white to brown 90V
From black and black/white to brown/white 90V
From black and black/white and white/brown 108V

Yes, the wires go directly to the trasformer, the black goes to the opposite side of the others. Yes I've said 230 but a few years ago was 220V, now the standard for italy is 230V with 10% tollerance :roll: I just measured with the voltmeter and gave me 228v, so I confirm 230 and so it is not enough...

Dear Martin, I was looking at the diagram and thinking about your words...and then I realized how stupid I am Maybe it is sufficient to connect the two windings in series instead of in parallel. I also have to replace the fuse with a half-current rating, right?

sorry!!! anodes

Ok, if you can get MC to help you with a diagram for that transformer that would be great I hope...but I don't think they replies me Otherwise, there are techniques that can be used for mapping out the connections. Maybe measuring impedance? I would like to learn those techniques I have tested the ...

The PT is pretty similar to this http://www.classictone.net/40-18042.pdf but mine has also a 100V winding and the colors of the wires doesen't corrispond. %Czcx8kBTny12yr9VmrQEQ.jpg The primary circuit is not like the fender one, the power switch and the fuse are in serial to the IEC power inlet and...

Now I’m not at home but I toke any pic, unfortunately I can’t load pics. On the transformer bell, under a blue tape, there are this digits: 40-17291 and 166-1027 made in usa. The transformer has 5 primary windings and two are linked togheter, I don’t know how. Tomorrow A friend gives to me a step do...

Hi to all! finally it's arrived,now I have to rewire for 230V, were I can find the specs with the colors relates to the primary tensions? In your opinion wich trasformers brand two rock use in their amplificators? How I can attach pics?