Thanks again for the response.
Have had something of a revelation: Hooked the lap-top up to the venerable Space-Tech via a Hagermann USB converter and am delighted with the sound. Still evaluating the detail but the richness is wonderful. Means I have to unplug the CD changer to connect the lap-top, but I have an open system, so all I have to do is trot up to the loft and switch cables (Think "Stair-stepping"). If the sound coninues to please, I will put the Nixon on the market: It's fine, but the Space Tech is "richer".