I asked my Luxman dealer about the 590ax being "fully balanced" and his response is below:
"Your Luxman amplifier is a fully balanced design when operated as an integrated amp. The connection between the pre-amplifier and amplifier is internal to the unit (it does not make use of the pre-out/main-in connections on the back panel in normal operation). When the 'separate' button is pressed you gain the ability to use either the preamplifier or amplifier sections individually although this does make a compromise of using the single-ended connections (this will obviously not be balanced).
As it will be a fairly rare instance in which you will use the pre-out or main-in functionality it was a reasonable design choice to make compromises in the implementation of this feature (were it done to reference level quality with balanced in and out there would be a substantial amount of additional expense and these larger connectors would take up valuable real-estate on the back panel of the unit, all for a feature that is quite rarely utilized)".
The above answers my question about my Luxman 590ax being balanced. A loaner Bricasti M1 DAC is expected next Wednesday. The question is how will my Ayre QB-9 DSD DAC compare to the Bricasti M1 DAC. I will take the advice above and listen using only one interconnect cable connected at a time (XLR balanced for integrated amplifier and RCA unbalanced for M1 DAC volume controls). This is probably the safest approach.
"Your Luxman amplifier is a fully balanced design when operated as an integrated amp. The connection between the pre-amplifier and amplifier is internal to the unit (it does not make use of the pre-out/main-in connections on the back panel in normal operation). When the 'separate' button is pressed you gain the ability to use either the preamplifier or amplifier sections individually although this does make a compromise of using the single-ended connections (this will obviously not be balanced).
As it will be a fairly rare instance in which you will use the pre-out or main-in functionality it was a reasonable design choice to make compromises in the implementation of this feature (were it done to reference level quality with balanced in and out there would be a substantial amount of additional expense and these larger connectors would take up valuable real-estate on the back panel of the unit, all for a feature that is quite rarely utilized)".
The above answers my question about my Luxman 590ax being balanced. A loaner Bricasti M1 DAC is expected next Wednesday. The question is how will my Ayre QB-9 DSD DAC compare to the Bricasti M1 DAC. I will take the advice above and listen using only one interconnect cable connected at a time (XLR balanced for integrated amplifier and RCA unbalanced for M1 DAC volume controls). This is probably the safest approach.