ABSTRACT
When people plan their first studios of any significant complexity, they are often shocked once they find the true cost of the cables and connectors needed to interface all the equipment. They tend to count carefully the cost of the items of equipment when preparing their budgets, but when everything is ready for installation, and the reality of the interconnection costs confront them, there is often not sufficient money left to do the equipment justice. It is always a great risk to cut corners on the audio cabling infrastructure because so many seemingly simple solutions can lead to traps. A simple lead, such as one connecting a phono (RCA) plug to stereo jack plug, may seem appropriate to connect the output of one device to the input of another, but there could be five or six ways of connecting those two ‘simple’ plugs. Although under many circumstances a signal will flow between the two pieces of equipment with any of the likely wiring arrangements, it is surprising to many people just how wrong some of those connections can be, and how they can degrade the sound without necessarily making any change in the measured frequency response. Figure 26.1 shows a range of possible methods of connecting the two
connectors mentioned above. In many cases, these get made in studios for specific purposes, but subsequently they get used for other purposes for which they ‘look right’, but are unsuitably connected. A typical example would be a cable which was perhaps being used to connect the unbalanced output from a CD player into the balanced tape return input of a mixing console, but which had originally been made to connect the transformer balanced output of compressor into an unbalanced input of a tape recorder. (The input and output function of each connector thus being reversed.) Whether or not it works in its new role is entirely dependent upon the type of balancing used in the input circuitry. The result of such a random interconnection may be noisy, it may be quiet, it may sound ‘perfect’ or it may sound degraded. The result of the incorrect wiring may be totally impossible to predict without knowledge of the precise type of circuitry to which it is connected, and which will not be described in most manuals for semi-professional equipment. The individual pieces of recording equipment in any studio really need to be brought to a common place of standardised termination if they are to be
flexibly and reliably connected together. The normal analogue way of doing this is via a 3-pole jackfield (or patchbay in US English). We currently have a state of affairs whereby equipment manufacturers
produce their equipment, often with little regard for how compatible it will be in its interconnection with other equipment. This is a more or less inevitable consequence of the evolution of much ‘semi-professional’ equipment out of the consumer market, where no interconnection standards were ever properly developed. In the realms of truly professional equipment there is less of a problem, because the professional equipment evolution has been more controlled.
