PCB Layout: Heater Traces / Wiring Best Practices

[Garthhog]

I have this amp I build... my HayMaker-50. It is currently a turret board / Point-to-Point hybrid (best way I can describe it). Anyway, I am considering converting it to PCB construction and I am trying to research best practices on layouts. I know that none of the rules change re: trace / wire proximity, etc. but I am wondering how to deal with the largest hum contributor: heater traces. I know that in a P2P or turret board build the wiring must be a TIGHT twisted pair right up to the sockets and all signal traces must cross at a 90 degree angle to keep crosstalk to a minimum. but on a PCB, unless you layout a fancy multilayer board with layer to layer ground vias, the heater trances have to live next to signal and control traces without the field cancelling benefits or shielding. So, I think there are a few options. One would be to make the heater wiring connection to the PCB right next to where each socket is soldered. Another would be to route heater traces East-West and signal traces North-South. Yet another is to leave the sockets as chassis mount, wire the heaters directly and run the signals to the PCB (same as turret board construction). Finally, I could just run DC heaters and worry less about crosstalk.

So, pros and luminous amateurs... which option would constitute a best practice when eliminating heater hum is of primary concern?

-Ryan

[gingertube]

Ryan,
If putting the heater traces on a PCB then you just about have to go 2oz copper board.
Many guys wire the heaters in a normal point to point fashion and just put the amp circuitry on the PCB.
Given the number of PCB based amps on which I have had to repair heater traces I would recommend this approach. (a couple of Mesa amps come to mind, a MK2C was the last I had trouble with this).
Cheers,
Ian

[Garthhog]

Thanks, Ian. I agree about the copper. Proper PCB design should prevent most trace burning.

[DonMoose]

Like Gingertube said, but wire direct to as close to the pin as you can get. There's a line of Oranges that tried to use a string of connectors on a twisted pair, and those just did not work.

[gingertube]

Thanks, Ian. I agree about the copper. Proper PCB design should prevent most trace burning.

And fuses on both sides of teh heater feed, rated at just less than the copper traces.

Cheers,
Ian