Impedance matching for analog interconnects

[Prune]

http://www.audiogeek.net/nitrogen/design.html
Scroll to the last section, "ProSink".

What do you guys think of the technical merits of this? According to discussion at head-fi.org, it uses a terminating resistor. I was under the impression that impedance matching didn't matter for audio frequencies unless the interconnects are very long.

[Jocko Homo]

Since I do have a background in "ultra high frequency radio"...........

There is some sense in terminating cables at the higher frequencies. But that is not what this guy says. if that is what he means, he has done a lousy job of explaining it.

It ends up sounding like typical audio hyperbole. Or ********. Take your pick.


Jocko

[Prune]

Gilmore gives proper explanation:
http://www5.head-fi.org/forums/showt...396#post813396
(post #72)
I'm wondering if doing this is worth the decrease in volume one will get. How much can it really affect quality?

[jackinnj]

Originally posted by Jocko Homo
Since I do have a background in "ultra high frequency radio"...........
Jocko

Perhaps every audiophile should have a Tek Time Domain Refloctemeter.

[Fred Dieckmann]

Try a 100 MHz or greater scope, a CMOS oscillator with a buffer to drive the cable , 20 ft of cable (to get enough propagation delay to see the reflection (spaced far enough away from the incident edge of the square wave) easily on the scope, and some RC networks to termninate the cable at the load end with the R being in the 50 to 150 ohm range and varied to match the characteristic impedance of the cable. your look for the reflections at the source end of the cable of course. I have used this techique to opitmize digital interface termination quite successfully. The idea of an RC termination is so the preamp doesn't have to drive a load as low as the characteristic impedance of the cable at audio frequencies where the capacitor impedance is much higher. The RC filter can be in the form of a low pass filter at the input to the amp ( ie the load end of the cable).