Soulution 511 vs. Luxman m900

Ouch...

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?