seanadams;368286 Wrote: > So what happens in each case if you get it wrong? > > Line levels: if the receiving device has a low input impedance (in > which case it is probably defective) or if the transmitting device has > a high impedance, what happens is that the signal becomes attenuated > <snip> This mainly just results in a reduction in volume, but may also > increase distortion depending on how the transmitter behaves in this > overloaded condition. > > High frequencies: if the impedance of the receiver is too high, the > signal will overshoot and kind of slop all over the place. If it's too > low, it will undershoot because energy is being reflected back to the > transmitter. In either case you get a distorted signal. In situations > where you must interface with a different impedance, you can use > transformers to make them match. >
I was meaning to come back to this, but you beat me to it! and much more clearly than I would have been as well... There is one further case that you haven't mentioned though. In many cases the inputs or outputs are capacitively coupled. In an ideal world, this capacitor value will be large enough to deal with any conceivable variations in source or input impedance. However, this isn't always the case, and occasionally frequency response issues can arise from this. Typically its a loss of low frequencies, caused by a small cap and a low input impedance creating a high pass filter with a corner frequency approaching audible frequencies. Those tend be extreme cases though, things like passive preamps, and while maybe not defective, they can certainly be called poor designs! -- DCtoDaylight Audiophile wish list: Zero Distortion, Infinite Signal to Noise Ratio, and a Bandwidth from DC to Daylight ------------------------------------------------------------------------ DCtoDaylight's Profile: http://forums.slimdevices.com/member.php?userid=7284 View this thread: http://forums.slimdevices.com/showthread.php?t=56068 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
