New Transformer on the Pole

It's very likely that the change in transformer was part of other changes in the utility's distribution circuit, including a possible change in the voltage of the distribution circuit itself, improvements made at the electric substation and even perhaps connection to another substation entirely. Electric distribution networks are dynamic systems and utilities frequently make changes to balance loads throughout the system. Any of these changes, including the new transformer, could conceivably affect your system.

almarg / cleeds -
curious about your feedback (no pun intended) here .... 

both of you have indicated that (paraphrasing) a change in line voltage could be the rationale as to the reason for a blacker background or perceived improvement. In my case I currently have virtually no "noise floor" (i.e. very black, etc.). Very happy in this regard! I am using a Panamax MR4300. That unit has a voltage level monitor.  My electricity service is provided by the "incorporated village" of Freeport and is known (rated) to be among the best overall electrical service in the US. 

My MR4300 consistently (when on or off and whether or not I'm listening to music) indicates the voltage is varying. It has measured as low as 116 and as high as 123. Regardless of the reading, I am unable to discern any audible difference. So my point in soliciting your feedback is to understand what degree of change you are speaking of, etc. Any other input is also appreciated.

@gdhal, my reference to a voltage change wasn't to the nominal voltage of your service, but to a possible change to the primary (distribution) voltage before it gets to your transformer. I speculate that because changing transformers is a pricey process and it was likely undertaken for a specific reason other than just just replacing an old transformer. But I am speculating, obviously.

Hi Hal,

The sensitivity of an audio component to line voltage variations will of course vary greatly among different designs.

I would expect, for example, that a well designed line-level component having a well regulated power supply will generally have little or no such sensitivity. Although even in that case it seems conceivable to me that sonic differences might sometimes occur, for example as a consequence of small changes in internal operating temperatures that would result from changes in line voltage, which would affect the power dissipated by linear regulators and hence their temperatures.

At the other end of the spectrum, though, a tube power amplifier having an unregulated power supply, in which both the filament voltages applied to the tubes and the high voltages applied to the tubes and other circuitry vary essentially in proportion to the line voltage, will have a great deal of sensitivity. In fact Atmasphere has mentioned in some past threads that he has measured a two volt difference in line voltage making as much as a 40% difference in the power capability of a tube amp. And with that difference in power capability a considerable difference in distortion performance seems to me to also be a likely result.

So as is usual in audio, it all depends :-)

Best regards,
-- Al
 

almarg / cleeds - 

Thanks! Your responses make sense (to me anyway, can't speak for the community at large). And further to your point almarg, I have a solid state amp, Musical Fidelity M6si and would have to believe a tube amp would be more discriminating where slight voltage variations occur.