Alternate AC power frequency.. Higher than 60Hz

The higher rail voltages with higher AC frequency erik_s mentions is a theory. One that would need to be tested to see if it is true. But in my opinion, the theory is faulty.                         
There is a difference (and i know you know too) between voltage and amperage. Beefier power supplies offer more amperage at the exact same voltage. Lots of upgraded power supplies are offered for electronics, without endless 'overload' dying of equipment (if it did die, the result would be hotly discussed here) So I have to say your theory, theoretically in my thinking about it, is wrong. 
I would agree there might be higher rail amperage.(Depending on the design of the power supply). But as I wrote, that is something plenty of folks do to tweak the equipment to sound better all the time.The voltage is not going to change.

I deleted my post as I must read more reference materials. I may have been confusing two different uses of similar terms. I leave you with this instead, which I am still digesting:

https://www.edn.com/design/components-and-packaging/4369085/Using-a-power-transformer-at-a-frequency...

It seems my memory of power vs. f may have been backwards, but using power supplies designed for one Hz with vastly different Hz seems bad. 

eric, the link was a good read. Mainly discussing using a transformer under two problematic conditions. Transformer made for 60Hz used at 50Hz, and one made for use at 400Hz (airplane Hz) used at 60/50. or reversed, using a made for 50/60Hz at 400Hz.(which are the only ’standard’ Hz usages at this time)There are problems with using a 60Hz designed transformer at 400Hz The wire used on each type is different, and the thinner wire in the 60Hz design is not suitable in 400Hz operation.(from a manufacturers standpoint) I do not know if 110 Hz is too much. (400Hz is 6.666 times the 60Hz operation, where 110 is less than 2 times. So that is a difference the article does not address) Clearly from my own use it may, or may not be a problem. (I used it mainly with digital gear, a DAC, no problem, One brand changer, no problem. But the Sony 555ES changer did overheat enough to shut down, where the Sony SCD9ES also no problem.) The 555 is a multichannel and the chassis is STUFFED full, no open space at all in there.
So thanks for the link.
ADDED and knowing the Marantz SA-10 transformer is sealed in a canister, I would think it a bad idea to run the Marantz at a higher Hz, Just sayin'.Plus I just turned down the Hz to 90Hz. that is only half again the rated Hz for the US based transformer.

elizibeth, I usually just read the post my writing skills aren't up to the task of public communication and my posting have always created cause for many to feel the need to give me English, spelling, grammar and punctuation lessons when I post, all free of charge :).

I have the same P600 and have run it at 90hertz, also frequently at P1 for many years. My stuff is old but it was new back when I got the P600 and now everything is old, like me, vintage and still working.

My stuff is Musical fidelity CD and DAC, the DAC is a tri vista and it has tubes, I think two, but so far no problems with it. My large Advents need all the help they can get!

The sound you hear is exactly what I hear but I attribute the "slightly leaner" sound to less bass extension at the higher hertz but yes to the better clarity overall, even the bass but with less extension. 90 looses some of that clarity but it will extend the bass. IMHO