Hey Gang,
I'm looking to DIY (well with some help) a new umbilical cord for my Supratek Syrah preamp.
It comes with a cord that's about 4 feet long made up of 6 wires. The stock wires are 18 gauge silver coated copper with FEP insulation. None of them are twisted pairs.
My DIY help guy tells me the wires carry the following signals:
1 & 7 = 6.3 VDC (filament)
2 = ground (chassis)
8 = 345 VDC
3 & 4 = 6 VAC
He tells me that, if I do twisted pairs, I should twist:
1 & 7;
2 & 8; and,
3 & 4.
I don't think it can be right that the ultimate wiring for all of these diverse signals should be the same gauge and construction of wire. There must be a technically ideal gauge and construction to match the voltage and current requirements of each signal.
Based on my experience with my CD player's tubed power supply umbilical, my preference is solid copper rather than silver. But I've read other posters suggesting that silver coated copper is the best thing for a DC umbilical.
On my limited technical knowledge, I'd be inclined to make twisted pairs, then to shield and ground each twisted pair.
In addition, I'm thinking about putting a Bybee filter on the 345 volt connection.
Technical comments welcome!
Thanks.
