3rd gen Heater Center Tap

[Fictitiousfreedom]

Hello amp obsessed friends! Quick question. Im at the stage where i have all my parts, face plate, chassis drilled, layout, ect.. and I'm just doubling over everything before i start putting it all together. It is almost exactly the amp from the generic 50w 3rd gen layout posted here. Only differences are that i did away with both the ground and standby switch, using slide switchs, and hammond Iron. I even found a modern box style relay with a socket and mount, its a 3PDT though. I come from making pedals so in the layout the relay looks a little like a 3pdt stomp switch, shouldn't be a problem as far as i can see. Sorry ill start a build thread soon.

If its been asked than i’m sorry i couldn't find it. My question has to do with the heater center tap. In the layout it shows what looks to be the heater centertap grounded at the transformer lug but in the schematic it shows an artificial center tap. I remember from my last build in a discussion on the el34 forum the guys were saying that you can have issues depending on how the relay foot switch is grounded in relation to the center tap of the heater circuit. I may be misremembering this but i wanted to be sure.

My foot switch jack is a Neutrik 5 pin that i got from apexjr, it has a big ground lug seperate from the 5 pins that connects to the body of the jack. So, should i connect anything to the ground tab, and also should i use the artificial CT as in the schematic or the transformers HCT? Thanks guys!!!

[GAStan]

The main PT heater windings are used for the tube heaters. There is plenty already posted on using the center tap vs artificial ground so I don't want to get into that discussion, just use the SEARCH function.

The footswitch uses a separate transformer. Do not ground the center tap on it, the ground reference for the relay is made at the voltage rectifier/doubler board. I only ground my 12vdc relay power return at the ground Lug near the small transformer used for this. I treat this return as a power wire-it does not get grounded anywhere else to prevent ground loops. It gets its own wire in the pedal cable just as the +12vdc does.

[Fictitiousfreedom]

The main PT heater windings are used for the tube heaters. There is plenty already posted on using the center tap vs artificial ground so I don't want to get into that discussion, just use the SEARCH function.

The footswitch uses a separate transformer. Do not ground the center tap on it, the ground reference for the relay is made at the voltage rectifier/doubler board. I only ground my 12vdc relay power return at the ground Lug near the small transformer used for this. I treat this return as a power wire-it does not get grounded anywhere else to prevent ground loops. It gets its own wire in the pedal cable just as the +12vdc does.

Thank you! That is exactly what i needed to know.

[GAStan]

Happy to help