User Manual

CABLE THEORY

Page 24

Most RF interference is not demodulated into an audio signal. The real problem is high frequency

energy from radio and TV stations, microwaves, radar, CBs and hundreds of other sources, includ-

ing your own stereo system! CD players must be registered with the FCC (Federal Communications

Commission) because they are sources of RFI. The same is true for tuners, TVs and computers.

The problem of RFI is not new, and neither is the most common solution. For decades, circuit design-

ers have used “ferrite beads” around wires to help block RFI. When the “beads” are large, and hinged

so that they can open and close, they are called “ferrite clamps”.

Ferrite reduces RFI in a cable by disrupting the radio frequency components of the magnetic eld

outside of the cable. For a current to travel within a cable, there must be an associated magnetic eld

on the outside. By altering the magnetic eld, ferrite is able to lter the current inside the cable even

though nothing has been inserted into the cable. No extra connections or electronic parts with their

own distortion problems.

situation RF Stoppers on the refrigerator’s power cable will reduce (not eliminate) the noise.

Because they lter very high frequencies so well, do not use RF Stoppers on digital and video cables.

Evaluation Methodology

How can something as simple as evaluating an audio component require serious thought? Don’t you

just listen and either there is a difference or there isn’t? If there is a difference, isn’t one better and

one worse?

YES! If you’ve never thought about equipment.

NO! If you have.

There is a fundamental distinction between listening to music versus listening to equipment. This is

denitely the conundrum of our industry: How can one judge the “vehicle’s” effectiveness without be-

coming preoccupied with the vehicle?

The very denition of good audio equipment is that it is not noticed, it is instead listened through. If

you view a far off landscape through a window, you would appreciate having a clean and undistorted

window to look through. If the task at hand is to judge the usefulness of the window, it is the visibility

of the view which must receive the viewer’s attention. A valid “test” would determine how much inter-

ference was caused by the window. It would be very unproductive for the eyes to focus on the window

itself. Focusing on any dirt on the glass would clearly destroy the ability to see and appreciate the

view, rendering the “evaluation” meaningless.

An important pitfall to avoid, is paying attention to the equipment, as that destroys one’s ability to

judge the effectiveness of the equipment. This articial separation of the equipment from its function

is possibly the most fundamental pitfall in the evaluation process.

Despite rampant references to “golden ears” and such, it is the truly inexperienced listener who most

easily appreciates differences and is able to establish hierarchy. Ironically, it is listeners with a total