I have started to do a Riaa based on a Croft Riaa, handdrawn schematic, with ECC83 tubes. I have two boxes, on for PSU and on for the Riaa. Filaments are supplied with 12Vdc from LM7812 reg. 250Vdc from a mosfet based reg is for the Riaa circuit.
I have the transformers in the PSU box, and also plan on having the filament 7812 reg in that box. GND is the same for the two regulators, But is it best to have on GND wire twistet with the 12VDC wire connected directly to only the fillaments in the riaa, and then another GND wire twisted with the 320VAC supplying the mosfet reg in the Riaa.
Or would it be better with on GND wire. Chassis is connected to GND through a X2 cap in the schematic. I guess the two chassis should be connected together with a separate wire.
I have the transformers in the PSU box, and also plan on having the filament 7812 reg in that box. GND is the same for the two regulators, But is it best to have on GND wire twistet with the 12VDC wire connected directly to only the fillaments in the riaa, and then another GND wire twisted with the 320VAC supplying the mosfet reg in the Riaa.
Or would it be better with on GND wire. Chassis is connected to GND through a X2 cap in the schematic. I guess the two chassis should be connected together with a separate wire.
http://www.valvewizard.co.uk/Grounding.pdf
Grounding
This third link shows how to get BIG Loop Areas if you are not careful.
http://www.geofex.com/Article_Folders/stargnd/stargnd.htm
Grounding
This third link shows how to get BIG Loop Areas if you are not careful.
http://www.geofex.com/Article_Folders/stargnd/stargnd.htm
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Valve heaters merely need a voltage reference, so you can run a separate 'GND' wire for them - just don't confuse it with the signal voltage reference.
I can't think what the point is of a cap between GND and chassis. You either connect them or you don't.
I can't think what the point is of a cap between GND and chassis. You either connect them or you don't.
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