New Transformer on the Pole


So, I got home yesterday and my wife told me that the power was out for a few hours while the town electrical department replaced the transformer on the pole across the street. I looked outside the window and saw the new transformer--much different (nicer, more modern) looking that the old one that I've been looking at for years. You know what I'm wondering......

So, last night I got a chance to fire up the rig and do some listening and I have to tell you that I heard some noticeable improvement in the sound. The background was "blacker" and there was a bit more purity and dimensionality. Am I just imagining this or could a "transformer upgrade" really deliver sonic gains?

dodgealum
I suspect that the likeliest explanation is simply that your line voltage changed somewhat as a result of the transformer change. Due to some combination of differences in their nominal turns ratios, differences in their turns ratios within whatever +/- tolerance they each have, and perhaps also differences in their internal resistance.

Another possible explanation is that the transformers perhaps have significantly different bandwidths, resulting in differences in the amplitude and spectral characteristics of noise that can be coupled through them from the high tension wires to your house wiring.

In any event, enjoy! Best regards,
-- Al

The newer transformers may have a lower inherent resistance/impedance. I don't know about old vs. new pole mounted, but for sure, pad mounted transformers tend to have much lower impedance, so much that the recommended AIR for service breakers may be higher if you have a pad mounted transformer than pole and are a short distance from the transformer.
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. 
Utilities change service pole top transformers for various reasons.
1.  The transformer is overloaded and a higher capacity VA transformer is needed.
2. The old transformer contained fluids that are no longer allowed in the utility industry and had to be replaced by a new transformer that in addition to having better internal oils, it has better specifications.
3.  The line loading off that transformer was sagging and a new/better transformer is needed.
4.  The voltage on the distribution line and loading may have exceeded the original ratings and required upgrades to the circuit.

Either way, a new transformer with higher (always better than the old transformer) VA rating will be much less noisy and perform better and also help prevent voltage/current sagging with higher loads.

Also, being one of the first homes off of a distribution pole top transformer is always a good thing.  Being the last on the last isn't very good.

enjoy

Darn I saw on the pole and thought this thread was about strippers. :p
New connections over old corroded ones.
Very interesting...thanks everyone for responding. I am the first feed off the pole and am enjoying the free upgrade!
Yes I was about to add also lower resistance due to new/cleaned connections.   Wish they did that here in Manhattan but everything is under ground.  
Everything matters