Princeton 6.3v Heater Wiring

Haych

On the Fender Princeton schematic the 6.3v heaters are connected via the pilot light, but it doesn't give a specific diagram for the actual connection, it just states "to all heaters".

Does it matter how the heaters are wired, I.E the polarity (not that this is mentioned at all) between pins 2 & 7 on the output tube sockets and pins 4/5 & 9 on the preamp tubes?

I take it that providing the sockets are wired consistently (Keeping the same pins fed from the same source wires across the various tube sockets) it should work ok?

Thanks, as ever, in advance.

Keefy

Yes it does. AC hum from the heater supply is proportional to the current flowing, so run the supply from the transformer to the following in order:

Pilot light
Output valves
Preamp valves in reverse order (first stages last)

Haych

Thanks @Keefy.  However, I was more interested in which wires (-/+) go to which pins rather than the specific order of which tubes are wired first.  The logical layout of the components in the chassis more or less dictates which sockets are wired first and last.

Does it matter which way the polarity connects to relevant pins of the sockets?  I assume it doesn't otherwise the schematic would say so, but I also assume it should be consistent, I.E., pins 4/5 and 9  on the preamp sockets and 2 & 7 on the output sockets all get juice from the same source, if that makes any sense?

springhead

It's an AC supply of 6.3V, there is no polarity to worry about like there could be with a DC supply feeding active components.

Some say that being consistent with the same half of the supply to same valve base pins matter, others say not.  I've not tested it either way but usually wire in a consistent fashion just in case.

Haych

Ah, great, that’s good to know. Thank you @springhead. ;

I’ll get the soldering iron out soon. 

Cheers

RiftAmps

springhead said:

It's an AC supply of 6.3V, there is no polarity to worry about like there could be with a DC supply feeding active components.

Sorry, I disagree. Mismatched phasing in a parallel AC heater circuit can cause all sorts of unwanted noise.

This is how I do it:

Octal pins 2 feeding Noval pins 4/5.

Octal pins 7 feeding Noval pins 9

springhead

Interesting. Other than keeping it consistent is there some absolute reason for your method ie what happens if you reverse the phase between the octal and noval valves?