Thanks for the replies everyone!
@jerrybj Yeah I was in the doghouse for a while. I went with the forgiveness over permission tactic, just about worked!
To answer the questions:
Brand new SCM40's. I've had them for about four weeks now. I listen everyday but have not done any specific 'burn in' process.
Chord Shawline X Speaker Cable
Chord Shawline Analogue XLR Cable
Supra USB Cable
I'm sorry to hear the RME might be inadequate, I had thought it a perfect solution and would leave the PS Audio S300 to do all the work. So the preamp is still important even with a power amp in the chain? That leaves me in a quandry as I've got space constraints. The preamp can not be taller than 12 cm, and must also incorporate a high end DAC. Any recommends would be appreciated. I thought about the Anthem STR but I'm a bit put off by the dac chip apparently not being the best.
As I say, this system is almost perfection, with the right recording that doesn't tickle the high end too much, the speakers sound unbelievable. Stick on a bit of Gordon Lightfoot, beautiful.
I'm steering towards the Sablon 2020 usb cable but fear it mightt be overkill.