You don’t need tracks as wide as 3.8 mm. While voltages may be high, currents in pre-amps with tubes such as the the ECC83 will only be in the milliamps so the default widths will be fine as the resistances will have no effect on your circuit (you can calculate them if you wish, using the calculator in KiCad), and you can increase them a bit as you have the space.
The exception is the heater lines. Those carry 150 or 300 mA I forget the exact figure, depending on whether the elements are in parallel or series for the ECC83 (6.3V or 12.6V respectively.
The size of the board is set by the edge cut lines that define the boundary of the board. See the KiCad documentation.
Depends on how much current you need to handle, but that’s very big compared to typical PCBs I usually work width. 1mm is usually maximum for high power tracks. You can use the “track width” tab in the KiCad PCB Calculator tool to calculate the right width given options such as current, conductor length and allowed temperature rise. If you don’t know the parameters, measuring the old tracks is probably your best bet.
It looks like you’re on the way to success! Good work.
Thus, this is somewhat useless but will post it anyway…
Short of doing a new PCB:
Option 1: Using a standard Drawing App that includes an Eraser Tool or similar) and clean-up the Image. Best to grab a fresh image from the Manual. Then, use the Bitmap Converter tool
Option 2:
Same as Option 1 but, use the an App’s Image Tools (with such things a Filters…etc) to enhance the image before using the Bitmap Converter…
With a fairly clean converted image, you can place it in Kicad PCB and use it as a guide for dropping parts on it and making traces
Very quick example of Option 1 (I did NOT try for perfection, just quickly grabbed an Eraser tool and erased some things for this example
FYI - I Never use DRC (especially if I haven’t a Schematic associated with the PCB). If you do a good, thorough review of the pcb (and, possibly have someone take a second look at it) you should be ok…
Set the DRC settings to reduce the catching of errors… several parameters you can modify…
In original PCB nets at both ends of R41 were surrounded by the copper connected to C6 left pin. It is possible that it was intended to shield that nets from leakage from other nets.You can’t be sure, but you can’t exclude this.
Unless I missed it above I don’t see that you have posted the KiCad schematic. I assume you have one, otherwise you wouldn’t have been able to generate the PCB and 3D view. I’m not volunteering to compare the schematic with the layout (original or generated) you have, or even with the original schematic in the service manual, that’s a lot of work to expect others to put in for you, but I can still glance at tube schematics and spot gross anomalies.
FYI - You don’t ‘Need’ and Schematic to make the PCB. You can add Footprints and Traces to a blank PCB and all the other stuff as if having a schematic.
Sure, a schematic makes for a complete project with other capabilities but, it’s Not required.
Well I started out saying that because the silkscreen image seemed to indicate all axial components including capacitors. (OK I guess the tubes are not axial.) But I edited that out because I then saw the 3d image shows what looks like some radial (maybe uncoated stacked film?) capacitors. I do not know if that type is still made, but once upon a time they were made by Siemens.
I use 1 mm tracks to connect (small-ish) 0805 footprints which I use for 0603 chips, unless there is not enough space for it. There are many situations where 1 mm is too wide, but (unless I am concerned about capacitive coupled crosstalk, etc. which is rare) I try to make tracks almost as wide as the pads to which they are connected. And sometimes I will vary the width to make them wider where there is space. I do not get a refund for etched copper, and wider tracks reduce inductance somewhat, particularly when there is a well-located ground plane. They are also more mechanically robust.
