Using step up / down transformers?

I am using ACUPWR step up transformers to run 230v subs /CD/DAC. Heavy duty build quality. Sounds identical to native 230v when the components were used in Europe.

ditusa

... 240 volts, double phase is more efficient then 120 volts, single phase. Maybe ask Jim jea48, about voltage and amperage ...

No, 240VAC is not more "efficient." Your equipment will operate at the same efficiency at either 120 VAC or 240VAC - and it will consume the same amount of current either way. Feel free to measure it for yourself.

I'd like to be more precise in regard to transformers on ac lines. I stand by what I said about diminished performance with my diy bucking transformer. I did suffer transient blunting and micro and macro dynamics suffered with trans. I'd like to make clear this was with 845 SET amp, this amp generates around 1000 internal watts and requires much current. I use dedicated ac line with 10 gauge special romex to feed. I've also  found my 845 amps or any of the other many tube amps I own do suffer from these same liabilities using any power conditioner, regardless of design, and I've tried many over the years.

Now, I do use a transformer based power conditioner on the rest of my system, this 82lb behemoth diy modded with high voltage film caps and Oyaide R1 receptacles. This has proven to be best pc for all the rest of my equipment. The amps do suffer with this pc.
IMO, amps should be on their own dedicated 10 gauge ac line, nothing else on that line.

@sns, 
''IMO, amps should be on their own dedicated 10 gauge ac line, nothing else on that line.''

I agree 1000%. 

Let's say that a 120 volt line (load) is drawing 10 amps. Since it is a single ended design, the draw will be carried by the hot conductor. 
 By the same token, using the same example of a 10 amp draw, a 220 volt line will still draw (or I should say the load will draw) 10 amps total, BUT since it is a Balanced design, each conductor would be drawing 5 amps. The total is the same. The word efficiency, may be applied to the fact that a smaller gauge wire can then be used. 
 I have heard however that there is an increase in efficiency of electric motors because the power is coming at opposite phases (times).