> I've been experiencing a reasonably audible hum from my Layla's power supply
> when I power it up. would this be a grounding problem? Or perhaps the power
> supply needs looking at? Also does anyone know much about power filters,
> spike protectors etc and how they may help?
Power filters and spike traps don't care for low frequencies.
The hum is probably the result of a not so perfect wiring.
Please try to move the mains plug of your Layla to the same
power strip your computer is plugged in and connect your
audio equipment to the same power strip.
I think we're trying to shoot a ground loop problem.
Tell us about your results