What makes an interconnect sound like it does?

And don't forget that an IC that is PERFECT in one place in your system may not work well at all in another. Just thought I'd throw that in to help ease your choices in wire.

Enjoy,
Bob

Loontoon,

As counter-intuituive as is may sound, I don't believe you *really* want to impedance match your components. Modern solid-state devices transfer voltage between products, not power. Optimum power transfer requires impedance matching. Optimum voltage transfer does not.

Today’s products have high input impedances and low output impedances. These are compatible with each other. Low impedance output stages drive high impedance input stages. This way, there is no loading, or signal loss, between stages. No longer concerned about the transfer of power, today’s low output/high input impedances allow the almost lossless transfer of signal voltages.

For example, the positive and negative outputs of the driving unit have an output impedance labeled ROUT. Each input has an impedance labeled RIN. Typically these are around 100 Ω for ROUT and 20k Ω for RIN. Georg Ohm taught us that 100 Ω driving 20k Ω (looking only at one side for simplicity) creates a voltage divider, but a very small one (-0.04 dB). This illustrates the above point about achieving almost perfect voltage transfer, if impedance matching is not done.

If it is done, you lose half your signal. Here’s how: impedance matching these units involves adding 100 Ω resistors (equal to ROUT) to each input (paralleling RIN). The new input impedance now becomes essentially the same as the output impedance (100 Ω in parallel with 20 kΩ equals 99.5 Ω), therefore matching. Applying Ohm’s law to this new circuit tells us that 100 Ω driving 100 Ω creates a voltage divider of ½. That is, ½ of our signal drops across ROUT and ½ drops across RIN, for a voltage loss of 6 dB. We lose half our signal in heat across ROUT. Not a terribly desirable thing to do.

Of course, I could be wrong. What the hell do I know?

Impedance matching ? The impedances are supposed to be mismatched (low output impedance, high input impedance). An RCA interconnect should transfer voltage, not current.

However if the source has an unusually high output impedance, and the destination has a rather low input impedance then this will cause distortion in the signal ... perhaps this is what loontoon was referring to ?

My guess (based on some personal experience) is that quality of connection and overall capacitance are the two keys. For connection quality make sure everything is really really clean, and free from oxidation. For low capacitance I think you'd have to avoid the shielded coax type interconnects, use as much air as dielectric as possible, and PTFE where a dielectric must be used.

I think silver is possibly the best conductor because even surface oxide is conductive, gold is a lousy conductor (relatively) but prevents oxide formation on terminations.

That said I think capacitance is much more importance than resistance so copper / silver may be a wash.

I always solder because I don't have crimping tools.