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I am finally assembling these parts, and I'm at the point where I am about to mount the transformers and wire up the heaters. This part of the instructions/layout is a little bit confusing to me, though, since what is written in the manual does not seem to match the layout, nor does it match my lmited concept of electrical common sense.

Ok, so on the layout, I see a twisted pair of black and purple wires linkng the heater pins of v1-v5. So far, not confusing. However, these wires are then connected to a single, isolated lug on the 5-terminal strip near the power transformer... Connected to nothing?

The instructions in the manual then say to "connect the two 6.3v heater wires from the transformer to the tag strip where the twisted heater wires were connected.". But, according to the diagram on the very same page, there is only ONE 6.3v wire (white) coming off the PT, but it is going to pin 5of the rectifier.

My guess is that the two green wires, labeled in the diagram as 3.15v each, are to somehow work together to create the 6.3v called for in the manual, but on the layout, the two green wires are connected, separately, to the 5 terminal strip, and again, not connected to anything else. Rather than play around with this expensive and potentially dangerous kit trying to figure this out myself, I hope someone on here will be able to clear up for me how this heater wiring should work.

Which layout are you looking at?

Let's look at the classic sIII 18W. Layout found in Resource section of the forum.
download/file.php?id=461&mode=view

Your right all the heater pins of tubes V1-V5 are connected together. Notice how the heater wires coming from the last tube (V5) then go to the 5 pin terminal trip. From the 5 pin terminal strip they connect to the heater windings of the transformer. The heater windings of the transformer would be the two green wires.


Btw the heater winding has whats called a center tap. The CT is the green/yellow wire that goes to ground. The heater will measure 6.3V from green to green or 3.15V from heater to ground. We usually measure voltages referencing ground that's why you see the heater winding labelled as 3.15V-3.15V on the transformer.

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This is the layout I have: download/file.php?id=471&mode=view

Looks like nothing's connected to the heaters at the strip.
Also, thanks for clearing up that voltage question. I was under the impression that I was to measure against zero.

That layout is defiantly wrong. Look at the sIII or Plexi layout for wiring the heaters. The TMB probably had a layout change and the heaters got moved or something, since it’s not the most built 18W version it probably just went unnoticed.

I’d email Stephen and tell him about it so he can change the layout.

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Ah, ok. It's much clearer on the sIII diagram.

So I'm assuming that I can connect either of the two green wires off the PT to either of the twisted wires going to the heaters - there's no concern for polarity here?

Thanks again for your help.

Heaters are an AC voltage so there is no polarity. Connect it either way and it's fine.

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AH, right! Back and forth

I think I'm catching on.

All the drawings are being updated as we speak. Will check on this one.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

We corrected the posted layout in the Resources Section. thanks for pointing that out.

See also viewtopic.php?f=12&t=3029

Manual updated with this picture as well.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Awesome! Thanks for the update and the detail pic.