Hardwiring, Layout Problems | Solutions To These Problems |
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Every design incorporates basic concepts; hardwiring and PC boards being included. In the old days, hardwiring was the staple of manufacturing. However, in the past 45 years or so, PC board construction evolved. Many have sought to return to "hardwiring" but not much attention has been paid concerning its shortcomings and if improvements are possible. When you consider solder contains some 60% tin (6 times the resistance of copper) and 35 to 40% lead (12 times the resistance of copper) one can see the importance of reducing solder connections. Better solder is an improvement, but certainly not a cure all. If "simple" solder connects make a difference, what about internal wiring, electrical fields? What about layouts, resistors, capacitors, stray capacitance to ground and stray capacitance between parts etc?
For instance, just one 2uf capacitor on the chassis can have as much as 7pf between it and ground (called stray capacitance), which should not be there. Any capacitance to ground reduces the high frequency response and causes phase shifts. Imagine what multiple parts and wires on or near the chassis can do. One can imagine the inconsistency problems, from unit to unit, during construction as parts layout varies from component to component. Then there is the problems of common wires and the electrical fields they generate that affect adjacent parts. Layout is extremely important.
Now, what if we could minimize the shortcomings of "hardwiring" and use only the pluses of PC boards? We will have improved on a classic concept and better sonics.
Now, let's check the pros and cons of PC boards.
The next page "Solutions To These Problems" will explain further.
*See "Picking Capacitors" by Walter Jung, Audio Magazine, Feburary, March 1980 for more information on capacitors.