You might want to invest in a small meter that can monitor your line voltage. If you are experiencing differences in line voltage, your system CAN change performance levels. Depending on how your amp / preamp is designed (unregulated, loosely regulated, tightly regulated, etc..), voltage changes can make a WORLD of a difference. This has to do with bias and feedback levels, etc... Some of this may also have to do with your mood, humidity levels, etc... It is for these reasons that we should all be listening in anechoic chambers that are temperature and humidity regulated. There should also be a very sexy "waitperson" serving us our beverage of choice and playing our favorite musical selections. Audio would be SO much better... : ) Sean
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