Might be a dumb Q

[ldervish]

Re: lead dress, am I right in thinking the OT primary B+ lead should not be bundled/twisted with the plate leads?

What about a B+ lead crossing heater wires near the socket?

Thanks in advance for your tolerance!

[Jazz P Bass]

I had a Fender 5B3 on the bench & noticed that the OT leads come up through the chassis & are literally twisted & knotted together to keep them from being pulled out through the chassis. (stressing the solder connections)
If your heaters are Vac I don't know that they should be near the B+.
Although the raw B+ is already pretty ripply by design.
A right angle crossing is better than parallel.

[ldervish]

I had a Fender 5B3 on the bench & noticed that the OT leads come up through the chassis & are literally twisted & knotted together to keep them from being pulled out through the chassis. (stressing the solder connections)
If your heaters are Vac I don't know that they should be near the B+.
Although the raw B+ is already pretty ripply by design.
A right angle crossing is better than parallel.

The heaters are a/c, crossing would be near the Y where they branch to 4+5 and 9

[Jazz P Bass]

Try it.
If they have to cross, do it at a right angle.

[Enzo]

Consider the context. The reason we do not bundle some wires is that some may be sensitive to what is in the others. SO all that 60Hz current through the heaters wires should be kept away from sensitive grid wires of the tubes.

SO bundling the three primary wires of the OT? Well, they are all next to each other inside the transformers, nothing bad happens. There can be hundreds of volts of signal on those power tube plates, but the B+ supply is not what we would call a high gain circuit, it would be tough for it to pick up some radiated signal.


It is always good practice to cross AC bearing wires at right angles if possible, but the B+ wire is not going to pick up much of anything. It has no gain.

[ldervish]

Much appreciated.