Signal degration over length, source vs. output ?


Which signal is more likely to degrade over length, source to amp, or amp to speaker? I have a pair of 300B monos on the way and don't know where to place them relative to preamp and speakers. Is it generally better to place the amps close to the pre-amp and use a short interconnect and a longer speaker cable or the other way around? Any insight would be appreciated.
jamesddurkin
Actually, my concern is the harmonic change due to very long speaker cables rather than power or voltage losses. In addition, living with a 10meter run for one or the other, I have experimented with both and found my preference. Of course, I generally use a preamp with a <50ohm output impedance and excellent voltage output.

In the OP's case, (and indeed in any other), best advice is to try both ways if one can.
If you have a solid state preamp with output impedance in the 50-100 ohm range, interconnects are not all that critical. As Kr4 says, impedances for this interface (preamp to power amp) are well defined, whereas the power amp-to-speaker impedance relationship is variable. Therefore go with long interconnects. I note that at recording sessions it is not uncommon to have a hundred feet of interconnect wire between microphones the mic preamp and the recorder.

If you have a tube preamp, with the typical 600ohm output impedance, keep the interconnects short.

These general rules apply for "decent" (affordable)wire. The disadvantages of long wires of either type can be overcome (so they say) by various kinds of exotic wire configurations, for which you will pay dearly.
I agree with what El and Kr4 are saying in terms of low output impedances being highly beneficial to this situation, but El is tossing out statements about long mic cables while forgetting to mention that these are all primarily runs of balanced / xlr cables. BIG differences in performance between xlr's and rca's on a long run.

Corona: If music consisted of a series of non-distorted sinusoidal waveforms, your comments would make more sense. Since it is quite possible to have notes that are not of equal amplitude / duration in positive and negative attributes, "diametric opposition" or having an "AC flywheel" doesn't come into play quite as much or as linearly as one might think. Then again, i might be misinterpreting what you are saying as you tend to "fly" with your "cloaking devices" pretty well maxed out.

Having said that, I do agree with your comments pertaining to field contamination. I have tried to get this point across to Audioengr in terms of shielding of cables only being bad when it is improperly applied. You may / may not agree with this, but judging from what i think you're getting at, i think that you would agree. Sean
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