Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Oddvar on September 07, 2019, 12:38:04 pm
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Hi. I am swapping a US transformer to a European one in a Caliber 50. Is there anything else in the circuit I have to change. The MOV capacitor f ex? Does it have to be 240v or more? The new transformer is made by TAD, it has two G/Y 0v's, but the Caliber uses 100r to ground, so what do I do with the two G7Y's since there are only one on the US Transformer?
Primary:
0 V Brown
230 V Black
240 V White
Secondary:
340V Red
50V Blue
0 V Green/Yellow
340V Red
3,15 V Green
0 V Green/Yellow
3,15 V Green
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from what I see;
you need the G/Y(goes where the R/Y was) from the 340-0-340 part for your HV secondary
you DON'T need the G/Y from the 3.15-0-3.15 part
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Thanks.
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Since there are two wires with the same coloring, y/g, is there any way to decide which is which?
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Since there are two wires with the same coloring, y/g, is there any way to decide which is which?
Use your ohm meter.
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Since there are two wires with the same coloring, y/g, is there any way to decide which is which?
Use your ohm meter.
One measure 72 ohm to red wire, the other has 1 ohm to green wire. Vice versa no reading?
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the 2 G/Y are part of 2 separate secondary's
one should read ~~ = from one red to the other
the OTHER G/Y should read ~~ = from one Green to the other
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One measure 72 ohm to red wire
Paint that wire red with a blue stripe.
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So I nearly have the info I need, but one thing remains. As one sees in the picture of the two primary sides of the the said transformers. The Mesa has a eight point plastic connector going into the board. There is on white and one black/white wire going into it. There is also a lone lead coming out of the opposite side of the bundle going into the connector. This goes to the standby knob. On the TAD transformer this corresponding wire is brown, but on the diagram that is the 0v. The 0v on the Mesa is white and goes into the connector. The 100v on the Mesa goes into the standby, does that mean that the 240v on the black wire is going into the standby, and the brown 0V is going to the Standby? May seem easy to some of you, but puzzles me, since the brown on the Tad and the brown on the Mesa comes out of the transformers as a single wire?
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DO NOT CONNECT ANY WIRE ON THAT PT TO THE STANDBY SWITCH!!!
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Sorry Sluckey. I meant the Power Switch.
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The Mesa's brown wire is only for parts of Japan. Does that apply?
KNOW what you are doing here! A mistake can burn the line-cord, maybe bench carpet house.
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The Mesa's brown wire is only for parts of Japan. Does that apply?
KNOW what you are doing here! A mistake can burn the line-cord, maybe bench carpet house.
I am trying to find out what I am doing, won't connect till I am sure. The transformer was supposed to be a drop in, but it's different.
I also wonder if I should change the pilot light to 240v, since it's connected directly to the mains, 125v wouldn't be good would it?