Created on 2013-07-23 20:59:00
AP Cable Quality
When is a cable not really a cable? When it allows noise and poor connection quality to mar audio measurements, a cable turns from a neutral wire into a source of trouble and additional cost.
At Audio Precision, we make the test instruments that the world uses to determine the quality of audio products, and so spend our time worrying about details that many audio developers can afford to ignore. We know that our analyzers must out-perform every product they test in order to deliver trustworthy results. That level of attention is extended to all aspects of our instruments, including the interconnects. Cables and connectors are frequently culprits in inaccurate or unstable measurements when one has an instrument capable of detecting very small non-linearities and noise. Anything less than perfect with respect to shielding, grounding or metal-to-metal contact is a potential source of problems.
Cables purchased directly from AP are not simply repackaged “off the shelf” products; they are custom-manufactured in order to meet our demanding specifications so that users of AP audio analyzers are assured that there is an absolute minimum of “weak links” in their audio test system.
An excellent example of AP’s attention to detail are our CAB-DBXF/M cables for the APx585. This cable type is terminated at one end with a DB25M connector, and at the other with 8 individual XLR connectors, and provides balanced analog I/O for the APx585.
A CAB-DB25M cable snake for use with the APx585
Each XLR connector has it’s own dedicated 3-conductor shielded cable, and all 8 cables are packaged into a single snake. Each balanced signal pair has a dedicated drain wire, and signal pairs are twisted to minimize crosstalk and noise. At each DB25 connector, grounds and signal wires are kept near to one another to minimize noise susceptibility. The cable shield maintains 100% coverage over the length of the cable, and is carefully terminated at each end with 360 degrees of connection to the cable case. Such meticulous construction requires hand assembly and inspection, which AP performs locally in order to maintain tight quality control.
Expert dressing keeps unshielded cable lengths to a minimum
Contrast this type of construction with a typical “DB25” cable that one may purchase for use with older computer printers; these cables do not distinguish signal pairs, and have no shielding whatsoever. While inexpensive and perfectly adequate for their intended purpose, such construction is wholly unsuitable for use in low-noise audio applications and could give wildly inaccurate results if used for audio test.
Cables and interconnects may seem simple, and that assumption may lead some to discount their effects upon the test system. At AP we take a holistic view, and offer complete systems that outperform all others end-to-end – cables included.