One Return or Two for Interconnects?

Thank you, everyone. Two returns it will be!

Hi Ken,

My feeling is that two paralleled returns and one "hot" conductor would be the preferable arrangement.

With unbalanced (rca) interconnects the return path (which is normally through the shield of a shielded cable) not only conducts the return current, but also connects the chassis of the two components, which in turn are connected to ac safety ground as well as to the internal circuit ground.

Therefore any ac-related voltage differences between the two chassis, which may be caused by differences in potential between the safety grounds of whatever outlets they are plugged into, and also by leakage paths in their power transformers and elsewhere, will result in extraneous noise currents flowing through the return conductors in common with signal return currents. The component receiving the signal has no way of distinguishing those extraneous currents from signal.

Lower resistance of the return path through the cable will tend to "short out" the differences in potential between the two chassis, and lessen any problems that might cause.

Good luck with your project!

-- Al

Whoops!!!... I see this is about Interconnects, not speaker wires. However, a similar argument would apply. There would theoretically be some loss of separation, but this would be miniscule because the input impedance is so much higher than the interconnect wire resistance.

Actually, it is the return wire that has some theoretical advantage to bi-wiring. (One signal and two returns).

If the return wire has any resistance the Low terminal of the woofer will have an attenuated (and probably distorted) woofer voltage on it, and, with a single return wire, this voltage is applied to the tweeter Low terminal instead of zero volts.

I leave it up to others to figure out if the effect is significant.

I intend to braid the wires which are unshielded - e.g., Kimber. The wires I'm using are 24 gauge Mundorf. I already have a Kimber connect from CD player to Preamp and do not have problems with RFI/EFI so I thought I might try this project which would replace the interconnect from pre to amp.

I tried this project before using 4 x 28 gauge Jupiter cotton insulated wires but found that the cotton insulation slipped down the wire when I was ready to solder to the RCAs. That, I figured wouldn't do as there was a good chance that uninsulated wires would touch! In that earlier arrangement I was going to use two wires each for the signal and return.

No problems. Also, how are you positioning the wires in relation to one another? Are they shielded independently? Explain your design.