120V or 240V

"240V will sound better"

Can you give any physics reason why?
The amp circuits require the same voltages and do not know how many turns are in the primary transformer. 240 will require a larger step down (higher turns ratio) than 120.(Isn't an amp really running on 5 or 12V?) I don't see how this would change any performace specs of the amp. I could see 240 being better on a tube amp, because the voltage needs to be stepped up, but on SS the voltage needs to be stepped down.

Power is power.... easy as PIE..... P = I x E.
Power = (watts, VA)
I = (amps)
E = (volts)

NEC 2008
210.6 Branch Circuit Voltage Limitations.
210.6 (A) Occupancy Limitation. In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the voltage shall not exceed 120 volts, nominal, between conductors that supply the terminals of the following:
(1) Luminaires (light fixtures)
(2) Cord-and-plug connected loads 1440 volt-amperes, nominal, or less or less than 1/4 hp.

If you are in USA, I recommend getting it set for 120V ... (6550)

I agree with 6550 .. if you think to stay in US you should buy the 120AC Voltage version.

I don't agree with someone who says gears born for 240V. don't sound same at 120V.
It's exactly the same!
We can debate about the AC power cords .. these sure are different! But not the trasformers

IMHO

Thank you all for your input!! I had talked with several folks (incl. dealer and distributor) who thought the 240V would sound a bit more airy. I have contemplated the resale issue as well and decided to go with the 120V version to not be limited to one outlet.

To answer 6550's question: I am from Germany and have known about SL for more than 20 years. I heard the Kraft 400 last year and was blown away. I am very partial to tube amplifiers, but the SL was the first amp that could compete. I had ordered a Kraft 300 stereo amp that, unfortunately, was damaged during shipping. It played well and sounded great, but had a few nicks. Nevertheless, I never heard better bass or more three-dimensional sound. Paired with a first-rate tube preamp, it also gets the mids right! To make a long story short, the shipping issue is finally settled and I decided to upgrade to the 250 monos.

I think you are proceeding correctly with the 120V version, for the reasons stated by the others who advocated doing that.

The only technical differences I can envision that would result from running on 240V are:

1)Less current would flow in the power wiring, the ac fuse and switch, and the primary of the power transformer. I would expect any sonic differences resulting from that to be subtle and unpredictable at most, and not necessarily in the direction of being better.

2)You would be exposing the ac input of the amps to noise or distortion that may be present unequally on both 120V phases, instead of what may be present on just one phase. That difference should be minimal since the 240V wiring you would be using is a dedicated run. But to the extent that there were any differences, they would probably be in the direction of making 120V operation preferable.

Re the dealer and others claiming that 240V is preferable, I question whether those claims are based on extensive and carefully controlled comparisons that eliminated other possible variables.

Regards,
-- Al