Mark IV Transformer Voltage tap question

[Random Hero]

How is it you find out exactly what your amp is wired for again? I'm pretty sure I know where the taps are, and where it is inside the chassis (up on it's own circuit board, towards the power switches, right?

What I'm wondering is, how is it you tell exactly what it's wired to? I remember it being something to do with colours I think, but I can't remember exactly what. A walkthrough of some type would be great, just to help me out.

Thanks.

 

[Random Hero]

Need answer!

 

[Boogiebabies]

A or B version ?

 

[Random Hero]

Early B, I believe

 

[Boogiebabies]

T1 - RED/BLK
T2 - Orange
0V - Blue

100V - BLK/WHT
117V - BLK
220V - BRN/WHT
230V - BRN/RED ( B Schem. says BRN/WHT)
240V - BROWN

 

[Random Hero]

T1 - RED/BLK
T2 - Orange
0V - Blue

100V - BLK/WHT
117V - BLK
220V - BRN/WHT
230V - BRN/RED ( B Schem. says BRN/WHT)
240V - BROWN

So what is it I'm looking for exactly? Is it just one wire and various taps marked in this manner?

 

[tony777]

T1 - RED/BLK
T2 - Orange
0V - Blue

100V - BLK/WHT
117V - BLK
220V - BRN/WHT
230V - BRN/RED ( B Schem. says BRN/WHT)
240V - BROWN

Does it mean that I can rewire a 117 Voltage version to 230/240 Volts?

 

[Random Hero]

OK, I opened her up and it's literally a bunch of wires coming from the transformer.

There's currently a brown, laced with red, connected. I would think that is 230V from what Boogiebabies said. I've also located the all brown wire, coming from the same point on the transformer.

Just attach that where the brown/red currently goes?

Pic -

 

[Boogiebabies]

If that is not an export, I do not know what is. All the export primary colors are there. The yellow should be a seconday 5V tap for a tube rectifier heater as this is the same transformer as the DR.

 

[Random Hero]

If that is not an export, I do not know what is. All the export primary colors are there. The yellow should be a seconday 5V tap for a tube rectifier heater as this is the same transformer as the DR.

It is?

 

[Boogiebabies]

The domestic primary should only have:

Black
Black/White
White

The one you have is awfully fat too !!!

 

[Random Hero]

The domestic primary should only have:

Black
Black/White
White

The one you have is awfully fat too !!!

Fat? lol, Fat how?

 

[Random Hero]

Boogiebabies, would you wire it to 240V or leave it at 230V? UK Voltage is officially 230V +10%/-6%, so it could theoretically get up to 253V, although that is rare.

 

[Boogiebabies]

I would leave it at 230.

 

[Random Hero]

I would leave it at 230.

Even though the UK voltage was 240V until a few years ago, when the tolerances changed rather than what we're actually getting? Aslong as 230V is safe even if it does get all the way up to 253V, which like I say, is unlikely, I'll leave it at that.

 

[Boogiebabies]

So your saying you want to swap the Brown/Red wire for the Brown ?

 

[Random Hero]

So your saying you want to swap the Brown/Red wire for the Brown ?

Would that be how to wire it to 240V? I mean, if it's not gonna be a problem running on between 230V-240V then I won't bother. I got told today that generally power in the UK is 230V now, and it's rare that you will see above 235V in most parts of the UK. That's not to say it doesn't happen, but ya know.

I also spoke to a local guy who builds amps, and he wires his to 230V. He also tech'd somebody's Road King the other day and set that to 230V so...

I just don't wanna risk my amp frying.

 

[Boogiebabies]

Yup.

I would still leave it.

 

[Random Hero]

Yup.

I would still leave it.

Rightio.