Likewise, is it safe to assume that the "x2" Setting is the Optimum for
a) Meridian Processor and DSP Users.........as they can handle the 24/88 Streams
b) For Analog Speaker Users using the Sooloos DAC's
c) For non-Meridian DAC Users, whose DAC's can handle 24/88 Inputs
Yes for all three.
which is why for b) there is no adjustment. The analogue DSP path will always be 'set' on x2 internally, irrespective of how a user sets the digital output.
I suppose that for c) some users may feel that direct is the correct setting, if their DACs have their own special upsampling system.
Rick