• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Heater Wiring - the Good the Bad and the Ugly

Hey guys just wondering if someone has
A suggestion on how best to connect the heater wires (thick red wires) coming from the transformer and going to the tube socket. I was thinking to keep the run short and connect the the first stage tube 6sn7 on the bottom. Another option would be to run to the last power tube (top
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).
 
So basically I'm asking if it's best to hook up the red heater wires to the first tube 6sn7 and keep the run short or hook them up to the last tube (kt-120) and have the run long. Because of the thickness of the wires and the size of the holes in the pins i can't fit more than 2 wires in any one hole.
Hopefully someone chimes in. I'd like connect on the weekend.
 
Hello.

If I have 6 valves (5x600mA and 1x2,5A), is it okay to run a twisted pair from each socket to heater PSU (DC supply)? That would allow me to experiment with different PSUs later.

Runing a single pair daisy chained leaves me with less options.

I recently completed a SET amp with 4 - 6.3v tubes, I used a terminal strip off the PT 6.3v and ran directly to each tube socket.
Amp is based on a Blueglow video build where he ran the heater wiring this way.
 
If I have 6 valves (5x600mA and 1x2,5A), is it okay to run a twisted pair from each socket to heater PSU (DC supply)? That would allow me to experiment with different PSUs later.
If you have a test bed with multiple permutations of heater supply, then the guidance for heater wiring is hard to apply.

I am building an amp that uses 4 x 6.3v heater tubes that also have 13.5v heater equivalents (E/PCL86), and I'd like to make it possible to reconfigure it for the cheaper tubes. I have tried to solve this by having 2 * 6.3v heaters in two parallel tracks, ending in two pairs of 2 * screw connectors. My transformer is 8-0-8 3.2A, so I have to add a bit of resistance to support both types. Either one half of the heater supply supply one parallel pair, or the whole heater winding supplies two parallel pairs in parallel (should be clearer in the diagram).

If this is not a testbed, then I think it is prudent not to defer some of the more fundamental decisions. The heater wiring does make a difference, and once it is done, it is hard to get at it again and change it if you are working point-to-point.
 

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