I'm building a G7-ish mic from the (single pattern) Aurycle kit. A few things are different, e.g., like the G7, it uses an EF86. I am however using the Aurycle PCB. (The stock Aurycle uses a 12A*7 but the circuit is very similar to that of the G7.)
About heater wiring: The Aurycle (schematic) puts the +6.3V to socket pins 4 and 5, with a capacitor (C11) connecting that line to ground. Heater current returns via the center tap on pin 9, and connects to ground.
Two questions about this arrangement:
1. What is the purpose of C11? Noise filtration, I assume?
2. The trace running the +6.3V is in the middle of the board; the current is returned to one of the ground buses on the side of the board, with everything else. (Here's the board layout) I'm certainly no genius with this stuff, but isn't this a potential noise source? I looked on the G7 PCB, and both + and - heater connections are wired with their own thick, parallel traces---the heater ground is maintained as a separate connection back to the plug.
I was considering skipping C11 and running the heater wires in a twisted pair directly from the plug to the tube socket. Thoughts?
About heater wiring: The Aurycle (schematic) puts the +6.3V to socket pins 4 and 5, with a capacitor (C11) connecting that line to ground. Heater current returns via the center tap on pin 9, and connects to ground.
Two questions about this arrangement:
1. What is the purpose of C11? Noise filtration, I assume?
2. The trace running the +6.3V is in the middle of the board; the current is returned to one of the ground buses on the side of the board, with everything else. (Here's the board layout) I'm certainly no genius with this stuff, but isn't this a potential noise source? I looked on the G7 PCB, and both + and - heater connections are wired with their own thick, parallel traces---the heater ground is maintained as a separate connection back to the plug.
I was considering skipping C11 and running the heater wires in a twisted pair directly from the plug to the tube socket. Thoughts?