Soulution 511 vs. Luxman m900

I have no relevant experience but I would point out that the input impedance of the Soulution 511 is an extremely low 2K (balanced only). That would make it unsuitable for use with the majority of tube-based preamps, and with some solid state preamps as well. That is not an issue with the Luxman.

I would note, though, that the Luxman’s balanced inputs have XLR pin 3 "hot" (i.e., non-inverted relative to the polarity of the signal on the red output terminal) and XLR pin 2 "cold" (i.e., inverted relative to the polarity of the signal on the red output terminal), that being the opposite of what is usual for USA-made equipment. So to maintain absolute polarity the + and - connections to the speakers would have to be interchanged at one end, assuming no other polarity inversions are present in the signal path. And doing that **might** be a problem if the speakers incorporate powered woofers, or are otherwise powered, as in that situation the signals on the amp’s + outputs **might** be connected to ground by the speakers, either directly or through some low impedance. (In that situation an alternative approach to achieving correct overall polarity would be to use a pair of XLR cables between the preamp and power amp which have the connections to pins 2 and 3 interchanged at one end).

In any event, depending on the preamp that is used the low input impedance of the Soulution is likely to be a far more serious concern than the Luxman’s polarity reversal.

Good luck. Regards,
-- Al

Both amps are excellent in their own merits and it’s all system dependent. Go listen to both amps in your own setup / system and decide which one would be a better match in your own setup/system.
It’s all about system synergy. There’s no such a thing as "one size fits all" in this hobby.

As suggested earlier by almarg due to extremely low input impedance on the Soulution 511 would make a preamp pairing a lot harder than the Luxman unless when paired with its matching Soulution preamp.
Something to be considered.

Yes the Luxman is pin 2- in its normal position, but it also has a setting for 2+.

@hiendmmoe Are you referring to the BAL LINE PHASE INV switch?

http://www.luxman.com/product/detail.php?id=19

@almarg Would you mind expanding a little on your statement

In that situation an alternative approach to achieving correct overall polarity would be to use a pair of XLR cables between the preamp and power amp which have the connections to pins 2 and 3 interchanged at one end

I plan on getting the m900u and trying it with the USA made Benchmark LA4 preamp. I plan on using XLR cables from pre to amp. Your statement above is my scenario. How does one actually interchange the connections to pins 2 and 3?

@hiendmmoe Thanks for pointing that out. I hadn’t noticed the "bal line phase" switch on the rear panel of the Luxman, which it seems safe to assume will take care of the polarity issue I described.

@yyzsantabarbara Although that switch makes it unnecessary to have the connections to pins 2 and 3 interchanged, typically that would be accomplished by ordering cables from a cable supplier that would be custom made in that configuration. Or by sending existing cables to the supplier, for them to rewire at one end. In some cases DIY ("do it yourself") might also be feasible.

Regards,
-- Al