120V or 240V

Whether they will work better one way or the other is something I can not address. (The obvious answer to that is to ask the manufacturer if one way or the other is better.)

However, if you are bringing this to the USA, then the resale value of a 240V unit will probably be less here in the states, because most people do not have 240V outlets in their stereo rooms.
(I certainly don't.)
So, if you want to sell it for top dollar, you would probably have to sell it to someone in a country that has 240V, which means shipping out of the USA. (I don't know about you, but that is something I don't like to do).

Something to think about.
Good Luck with your decision!

The obvious answer to that is to ask the manufacturer if one way or the other is better.

I agree with Kurt tank......
Something else to think about, after market power cords. You can not use a standard NEMA 5-15R or a 5-20R 120 V receptacle on a 240V branch circuit.

If you are in USA, I recommend getting it set for 120V. This will make resale (which imo, is smart to consider) much much easier. I know of some real great amp deals at the moment, but they are "shelf-huggers" due to the fact that they are 220V models. If the were only 120, they would have sold in a day.
I see no sonic benefit to a SS state amp running on 220, since the voltage must be stepped down to the same voltage for the boards,(the 220 amp has the same everything except the transformer) so it does not really matter what the line V is.

PS. How do you know about SL ? How would you rank them with other brands that are better known in the US ?

I have a local dealer that can get that brand, but with no floor samples, I would never take a chance but I almost did.

240V will sound better

"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

A third possible difference, that I should have included in my previous post:

3)Leakage currents between the ac input and chassis/circuit ground in the amp, that might flow through parasitic capacitances or resistances in the power transformer, would be greater with 240V applied than with 120V. I would expect those currents to most likely be insignificant, but if there were any significance it would be in the direction of favoring 120V.

-- Al

If the resale value is much greater in europé for à 240v than 120v in us, the 240v might be a better investment, in economic terms, not necessarily in convenience though.

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... DRV

Symphonic Line Kraft 400 .. wow!!!.. whatta fantastic Amps!!!!
I can understand you .. DRV... I listened one time in Milano .. and your comparison to tube amps sound is totally true!

A third possible difference, that I should have included in my previous post:

3)Leakage currents between the ac input and chassis/circuit ground in the amp, that might flow through parasitic capacitances or resistances in the power transformer, would be greater with 240V applied than with 120V. I would expect those currents to most likely be insignificant, but if there were any significance it would be in the direction of favoring 120V.
01-07-10: Almarg

Al, I was thinking the same thing..... Wonder what effect equipment fed from 240V as well as 120V connected together by ics would be? Possibly a greater chance of a ground loop?
Jim

Good point, Jim, and that does seem conceivable to me, especially if the interconnects to this amp are single-ended (I don't know if they are single-ended or balanced).

With the amps running off of 240V, both sides of the primary of the power transformer in each amp would be 120V removed from chassis and circuit ground, conceivably increasing the degree to which leakage currents would tend to affect chassis potential, at least at noise frequencies and perhaps at hum frequencies as well. And with the preamp powered by 120V, the ac safety ground wiring would be unlikely to be effective at keeping the amp and preamp chassis at the same potential, because the inductance and resistance of the run between each component and the electrical panel is in that path. So the likelihood of inter-chassis noise currents flowing through the interconnect shields would seem to be increased.

So of the several factors we've identified that could conceivably result in sonic differences between the 120V and 240V versions, the majority of them point in the direction of the 120V version sounding better. Not that that means too much, of course; the only way to judge would be via carefully controlled listening comparisons.

Best regards,
-- Al