Hi, There's an error on the first current source. The string of 22k resistors should connect to the collector of Q4, not the base of Q1.
More fundamentally though, one of the reasons the Naim preamps as a whole are sensitive to power supply quality is that noise from that is injected into the signal via the 270K resistor at the start of the circuit. One of the ideas behind splitting the rails is to avoid this by referencing that point to ground but the way you have drawn it you'll be injecting the noise from both the +12v psu and the -12v psu into the same point.
As an aside, the noise injection at that point in the standard Naim configuration isn't quite as bad as simulation might suggest because of the (hopefully) low output impedance from the previous stage.